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HomeMy WebLinkAbout2024-02-20 Rail Committee Agenda PacketRAIL COMMITTEE Special Meeting Tuesday, February 20, 2024 Community Meeting Room & Hybrid 2:30 PM Rail Committee meetings will be held as “hybrid” meetings with the option to attend by teleconference/video conference or in person. To maximize public safety while still maintaining transparency and public access, members of the public can choose to participate from home or attend in person. Information on how the public may observe and participate in the meeting is located at the end of the agenda. Masks are strongly encouraged if attending in person. The meeting will be broadcast on Cable TV Channel 26, live on YouTube https://www.youtube.com/c/cityofpaloalto, and streamed to Midpen Media Center https://midpenmedia.org. VIRTUAL PARTICIPATION CLICK HERE TO JOIN (https://cityofpaloalto.zoom.us/j/86388142528) Meeting ID: 863 8814 2528    Phone: 1(669)900‐6833 PUBLIC COMMENTS Public comments will be accepted both in person and via Zoom for up to three minutes or an amount of time determined by the Chair. All requests to speak will be taken until 5 minutes after the staff’s presentation. Written public comments can be submitted in advance to city.council@CityofPaloAlto.org and will be provided to the Council and available for inspection on the City’s website. Please clearly indicate which agenda item you are referencing in your subject line. PowerPoints, videos, or other media to be presented during public comment are accepted only by email to city.clerk@CityofPaloAlto.org at least 24 hours prior to the meeting. Once received, the  Clerk will have them shared at public comment for the specified item. To uphold strong cybersecurity management practices, USB’s or other physical electronic storage devices are not accepted. Signs and symbolic materials less than 2 feet by 3 feet are permitted provided that: (1) sticks, posts, poles or similar/other type of handle objects are strictly prohibited; (2) the items do not create a facility, fire, or safety hazard; and (3) persons with such items remain seated when displaying them and must not raise the items above shoulder level, obstruct the view or passage of other attendees, or otherwise disturb the business of the meeting. CALL TO ORDER PUBLIC COMMENT  Members of the public may speak to any item NOT on the agenda.  VERBAL UPDATE ON INTERAGENCY ACTIVITIES A.Caltrain B.VTA C.City Staff ACTION ITEMS 1.Review the updated Summary of Evaluation Matrix based on the updated Council Adopted Criteria for evaluation of the grade separation alternatives STUDY SESSION FUTURE MEETINGS AND AGENDAS Members of the public may not speak to the item(s) ADJOURNMENT PUBLIC COMMENT INSTRUCTIONS Members of the Public may provide public comments to teleconference meetings via email, teleconference, or by phone. 1. Written public comments may be submitted by email to city.council@cityofpaloalto.org. 2. For in person public comments please complete a speaker request card located on the table at the entrance to the Council Chambers and deliver it to the Clerk prior to discussion of the item. 3. Spoken public comments using a computer or smart phone will be accepted through the teleconference meeting. To address the Council, click on the link below to access a Zoom‐based meeting. Please read the following instructions carefully. You may download the Zoom client or connect to the meeting in‐ browser. If using your browser, make sure you are using a current, up‐to‐date browser: Chrome 30 , Firefox 27 , Microsoft Edge 12 , Safari 7 . Certain functionality may be disabled in older browsers including Internet Explorer. Or download the Zoom application onto your smart phone from the Apple App Store or Google Play Store and enter in the Meeting ID below. You may be asked to enter an email address and name. We request that you identify yourself by name as this will be visible online and will be used to notify you that it is your turn to speak. When you wish to speak on an Agenda Item, click on “raise hand.” The Clerk will activate and unmute speakers in turn. Speakers will be notified shortly before they are called to speak. When called, please limit your remarks to the time limit allotted. A timer will be shown on the computer to help keep track of your comments. 4. Spoken public comments using a phone use the telephone number listed below. When you wish to speak on an agenda item hit *9 on your phone so we know that you wish to speak. You will be asked to provide your first and last name before addressing the Council. You will be advised how long you have to speak. When called please limit your remarks to the agenda item and time limit allotted. CLICK HERE TO JOIN    Meeting ID: 863‐8814‐2528   Phone: 1‐669‐900‐6833 Americans with Disability Act (ADA) It is the policy of the City of Palo Alto to offer its public programs, services and meetings in a manner that is readily accessible to all. Persons with disabilities who require materials in an appropriate alternative format or who require auxiliary aids to access City meetings, programs, or services may contact the City’s ADA Coordinator at (650) 329‐2550 (voice) or by emailing ada@cityofpaloalto.org. Requests for assistance or accommodations must be submitted at least 24 hours in advance of the meeting, program, or service.  1 Special Meeting February 20, 2024 Materials submitted after distribution of the agenda packet are available for public inspection at www.cityofpaloalto.org/agendas RAIL COMMITTEESpecial MeetingTuesday, February 20, 2024Community Meeting Room & Hybrid2:30 PMRail Committee meetings will be held as “hybrid” meetings with the option to attend byteleconference/video conference or in person. To maximize public safety while still maintainingtransparency and public access, members of the public can choose to participate from home orattend in person. Information on how the public may observe and participate in the meeting islocated at the end of the agenda. Masks are strongly encouraged if attending in person. Themeeting will be broadcast on Cable TV Channel 26, live onYouTube https://www.youtube.com/c/cityofpaloalto, and streamed to Midpen MediaCenter https://midpenmedia.org.VIRTUAL PARTICIPATION CLICK HERE TO JOIN (https://cityofpaloalto.zoom.us/j/86388142528)Meeting ID: 863 8814 2528    Phone: 1(669)900‐6833PUBLIC COMMENTSPublic comments will be accepted both in person and via Zoom for up to three minutes or anamount of time determined by the Chair. All requests to speak will be taken until 5 minutesafter the staff’s presentation. Written public comments can be submitted in advance tocity.council@CityofPaloAlto.org and will be provided to the Council and available for inspectionon the City’s website. Please clearly indicate which agenda item you are referencing in yoursubject line.PowerPoints, videos, or other media to be presented during public comment are accepted onlyby email to city.clerk@CityofPaloAlto.org at least 24 hours prior to the meeting. Once received,the  Clerk will have them shared at public comment for the specified item. To uphold strongcybersecurity management practices, USB’s or other physical electronic storage devices are notaccepted. Signs and symbolic materials less than 2 feet by 3 feet are permitted provided that: (1) sticks, posts, poles or similar/other type of handle objects are strictly prohibited; (2) the items do not create a facility, fire, or safety hazard; and (3) persons with such items remain seated when displaying them and must not raise the items above shoulder level, obstruct the view or passage of other attendees, or otherwise disturb the business of the meeting. CALL TO ORDER PUBLIC COMMENT  Members of the public may speak to any item NOT on the agenda.  VERBAL UPDATE ON INTERAGENCY ACTIVITIES A.Caltrain B.VTA C.City Staff ACTION ITEMS 1.Review the updated Summary of Evaluation Matrix based on the updated Council Adopted Criteria for evaluation of the grade separation alternatives STUDY SESSION FUTURE MEETINGS AND AGENDAS Members of the public may not speak to the item(s) ADJOURNMENT PUBLIC COMMENT INSTRUCTIONS Members of the Public may provide public comments to teleconference meetings via email, teleconference, or by phone. 1. Written public comments may be submitted by email to city.council@cityofpaloalto.org. 2. For in person public comments please complete a speaker request card located on the table at the entrance to the Council Chambers and deliver it to the Clerk prior to discussion of the item. 3. Spoken public comments using a computer or smart phone will be accepted through the teleconference meeting. To address the Council, click on the link below to access a Zoom‐based meeting. Please read the following instructions carefully. You may download the Zoom client or connect to the meeting in‐ browser. If using your browser, make sure you are using a current, up‐to‐date browser: Chrome 30 , Firefox 27 , Microsoft Edge 12 , Safari 7 . Certain functionality may be disabled in older browsers including Internet Explorer. Or download the Zoom application onto your smart phone from the Apple App Store or Google Play Store and enter in the Meeting ID below. You may be asked to enter an email address and name. We request that you identify yourself by name as this will be visible online and will be used to notify you that it is your turn to speak. When you wish to speak on an Agenda Item, click on “raise hand.” The Clerk will activate and unmute speakers in turn. Speakers will be notified shortly before they are called to speak. When called, please limit your remarks to the time limit allotted. A timer will be shown on the computer to help keep track of your comments. 4. Spoken public comments using a phone use the telephone number listed below. When you wish to speak on an agenda item hit *9 on your phone so we know that you wish to speak. You will be asked to provide your first and last name before addressing the Council. You will be advised how long you have to speak. When called please limit your remarks to the agenda item and time limit allotted. CLICK HERE TO JOIN    Meeting ID: 863‐8814‐2528   Phone: 1‐669‐900‐6833 Americans with Disability Act (ADA) It is the policy of the City of Palo Alto to offer its public programs, services and meetings in a manner that is readily accessible to all. Persons with disabilities who require materials in an appropriate alternative format or who require auxiliary aids to access City meetings, programs, or services may contact the City’s ADA Coordinator at (650) 329‐2550 (voice) or by emailing ada@cityofpaloalto.org. Requests for assistance or accommodations must be submitted at least 24 hours in advance of the meeting, program, or service.  2 Special Meeting February 20, 2024 Materials submitted after distribution of the agenda packet are available for public inspection at www.cityofpaloalto.org/agendas RAIL COMMITTEESpecial MeetingTuesday, February 20, 2024Community Meeting Room & Hybrid2:30 PMRail Committee meetings will be held as “hybrid” meetings with the option to attend byteleconference/video conference or in person. To maximize public safety while still maintainingtransparency and public access, members of the public can choose to participate from home orattend in person. Information on how the public may observe and participate in the meeting islocated at the end of the agenda. Masks are strongly encouraged if attending in person. Themeeting will be broadcast on Cable TV Channel 26, live onYouTube https://www.youtube.com/c/cityofpaloalto, and streamed to Midpen MediaCenter https://midpenmedia.org.VIRTUAL PARTICIPATION CLICK HERE TO JOIN (https://cityofpaloalto.zoom.us/j/86388142528)Meeting ID: 863 8814 2528    Phone: 1(669)900‐6833PUBLIC COMMENTSPublic comments will be accepted both in person and via Zoom for up to three minutes or anamount of time determined by the Chair. All requests to speak will be taken until 5 minutesafter the staff’s presentation. Written public comments can be submitted in advance tocity.council@CityofPaloAlto.org and will be provided to the Council and available for inspectionon the City’s website. Please clearly indicate which agenda item you are referencing in yoursubject line.PowerPoints, videos, or other media to be presented during public comment are accepted onlyby email to city.clerk@CityofPaloAlto.org at least 24 hours prior to the meeting. Once received,the  Clerk will have them shared at public comment for the specified item. To uphold strongcybersecurity management practices, USB’s or other physical electronic storage devices are notaccepted.Signs and symbolic materials less than 2 feet by 3 feet are permitted provided that: (1) sticks,posts, poles or similar/other type of handle objects are strictly prohibited; (2) the items do notcreate a facility, fire, or safety hazard; and (3) persons with such items remain seated whendisplaying them and must not raise the items above shoulder level, obstruct the view orpassage of other attendees, or otherwise disturb the business of the meeting.CALL TO ORDERPUBLIC COMMENT Members of the public may speak to any item NOT on the agenda. VERBAL UPDATE ON INTERAGENCY ACTIVITIESA.CaltrainB.VTAC.City StaffACTION ITEMS1.Review the updated Summary of Evaluation Matrix based on the updated CouncilAdopted Criteria for evaluation of the grade separation alternativesSTUDY SESSIONFUTURE MEETINGS AND AGENDASMembers of the public may not speak to the item(s) ADJOURNMENT PUBLIC COMMENT INSTRUCTIONS Members of the Public may provide public comments to teleconference meetings via email, teleconference, or by phone. 1. Written public comments may be submitted by email to city.council@cityofpaloalto.org. 2. For in person public comments please complete a speaker request card located on the table at the entrance to the Council Chambers and deliver it to the Clerk prior to discussion of the item. 3. Spoken public comments using a computer or smart phone will be accepted through the teleconference meeting. To address the Council, click on the link below to access a Zoom‐based meeting. Please read the following instructions carefully. You may download the Zoom client or connect to the meeting in‐ browser. If using your browser, make sure you are using a current, up‐to‐date browser: Chrome 30 , Firefox 27 , Microsoft Edge 12 , Safari 7 . Certain functionality may be disabled in older browsers including Internet Explorer. Or download the Zoom application onto your smart phone from the Apple App Store or Google Play Store and enter in the Meeting ID below. You may be asked to enter an email address and name. We request that you identify yourself by name as this will be visible online and will be used to notify you that it is your turn to speak. When you wish to speak on an Agenda Item, click on “raise hand.” The Clerk will activate and unmute speakers in turn. Speakers will be notified shortly before they are called to speak. When called, please limit your remarks to the time limit allotted. A timer will be shown on the computer to help keep track of your comments. 4. Spoken public comments using a phone use the telephone number listed below. When you wish to speak on an agenda item hit *9 on your phone so we know that you wish to speak. You will be asked to provide your first and last name before addressing the Council. You will be advised how long you have to speak. When called please limit your remarks to the agenda item and time limit allotted. CLICK HERE TO JOIN    Meeting ID: 863‐8814‐2528   Phone: 1‐669‐900‐6833 Americans with Disability Act (ADA) It is the policy of the City of Palo Alto to offer its public programs, services and meetings in a manner that is readily accessible to all. Persons with disabilities who require materials in an appropriate alternative format or who require auxiliary aids to access City meetings, programs, or services may contact the City’s ADA Coordinator at (650) 329‐2550 (voice) or by emailing ada@cityofpaloalto.org. Requests for assistance or accommodations must be submitted at least 24 hours in advance of the meeting, program, or service.  3 Special Meeting February 20, 2024 Materials submitted after distribution of the agenda packet are available for public inspection at www.cityofpaloalto.org/agendas Rail Committee Staff Report From: City Manager Report Type: ACTION ITEMS Lead Department: Transportation Meeting Date: February 20, 2024 Report #:2401-2503 TITLE Review the updated Summary of Evaluation Matrix based on the updated Council Adopted Criteria for evaluation of the grade separation alternatives RECOMMENDATION Review the updated Summary of Evaluation Matrix based on the updated Council Adopted Criteria for evaluation of the grade separation alternatives EXECUTIVE SUMMARY On June 12, 2023 City Council approved the updated Council Adopted Criteria for evaluating grade separation alternatives and directed the staff to incorporate elements from the discussion to update the evaluation criteria. The project consultant has conducted additional analyses based on the Rail Committee review and direction. This agenda item brings forth the updated The Summary of Evaluation Matrix reflecting updates to following elements for Rail Committee’s review and evaluation of alternatives. A. East-West connectivity B. Traffic C. Pedestrian / bicycle circulation F. Private Property Impacts G. Environmental impacts I. Visual impacts BACKGROUND In September 2017, the City Council adopted the evaluation criteria in selecting a preferred solution (a preferred alternative for each crossing) that included elements related to East-West connectivity, Traffic congestion, Pedestrian / Bicycle circulation, Rail Operations, Costs, Environmental Impacts, Visual Impacts, Local Access, Right Of Way Cost, and Construction. Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 1  Packet Pg. 4 of 57  The Matrix with a Summary of Evaluation based on Council Adopted Criteria was later developed and refined through the Extended Community Advisory Panel (XCAP) for review of the alternatives in consideration at Churchill Avenue, Meadow Drive, and Charleston Road crossings. This matrix assisted XCAP in making recommendations of preferred alternatives to the City Council. At the April 26, 2023 (Staff Report 2304-12691) Rail Committee meeting the evaluation criteria were further discussed and approved with additional elements for recommend. The updated Council Adopted criterial recommended by the Rail Committee was later approved by the City Council on June 12, 2023 (Staff Report 2305-14262) The updated Council Adopted Evaluation Criteria is as follows: A.East-West connectivity – Facilitate movement and connectedness across the corridor for all modes of transportation B.Traffic congestion – Reduce automobile delay and congestion for automobile traffic at rail crossings to consider corridor travel times and to reduce traffic inducement C.Pedestrian / bicycle circulation – Provide clear and safe routes for pedestrians and bicyclists seeking to cross the rail corridor, separate from automobile traffic through and after grade separation construction D.Rail operations – Support continued rail operations and Caltrain service improvements E.Cost – Consider Project Cost including Utility Relocation, Long Term Maintenance, and Financing of the project with feasible funding sources. F.Private Property Impacts – Minimize right-of-way acquisition. G.Environmental impacts – Review Sustainability, Sea Level Rise impacts, and Reduce rail noise and vibration along the corridor. H.Local access – Maintain or improve access to neighborhoods, parks, schools and other destinations along the corridor while reducing regional traffic on neighborhood streets. I.Visual impacts – Consider visual and privacy changes along the rail corridor. J.Construction – Minimize disruption and the duration of construction ANALYSIS Based on the new and updated Council Adopted criteria, the project consultant conducted further analysis to determine the impact on various alternatives. The analyses prepared for the following elements assisted in update the Summary of Evaluation Matrix that is based on the updated Council Adopted Evaluation Criteria (Attachment A) Traffic Analysis: Hexagon Traffic consultant conducted an additional analysis to review the automobile congestion and delay for the alternatives in consideration. The Analysis provided an assessment of east/west connectivity across Alma Street and the Caltrain tracks, focusing on travel 1 https://cityofpaloalto.primegov.com/meeting/document/2007.pdf?name=Item%202%20Staff%20Report 2 https://cityofpaloalto.primegov.com/meeting/document/2154.pdf?name=Item%206%20Staff%20Report Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 2  Packet Pg. 5 of 57  time/delay for motor vehicles and travel time/safety for bicycles and pedestrians for the grade separation alternatives at Churchill Avenue, Meadow Drive, and Charleston Road (Attachment B – Hexagon Memorandum on Palo Alto Grade Separation Bicycle and Pedestrian Analysis). This analysis supported the update to Summary of Evaluation Matrix. Churchill Avenue: For the Churchill crossing, two alternatives are under consideration: closure and a partial underpass. The partial underpass would permit turns from Alma to Churchill under the railroad but would restrict through traffic on Churchill Avenue. Both options include a bike/pedestrian underpass, enhancing safety for cyclists and pedestrians. While motor vehicle delay would decrease for permitted movements, some existing movements would be eliminated, and thus alternate routes would be required. Meadow Drive & Charleston Road: Meadow and Charleston railroad crossings currently have four three alternatives in consideration: Trench, Hybrid, Viaduct and Underpass. The trench and hybrid options would lower the railroad, with Meadow and Charleston passing over. Similarly, the viaduct option would raise the railroad, with Meadow and Charleston passing under. Traffic signals at Alma Street would persist, causing delays at red lights for motor vehicles, bicycles, and pedestrians. However, delays at the railroad crossings would be eliminated. The similar conditions will persist for Viaduct Alternative. For the Underpass alternative, Meadow and Charleston would pass under both Alma Street and the railroad. The Underpass option would therefore generally result in lower vehicular delays compared to the Trench/Hybrid alternatives. However, some vehicular movements would experience increased delays due to the circuitous nature of the maneuvers, requiring the use of the Alma Village Circle signal or the Charleston roundabout. The study evaluated and compared the delay for various movements. With the Underpass option, pedestrians and bicyclists on Meadow Drive and Charleston Road would not need to interact with motor vehicles to cross Alma Street. However, the proposed bike/pedestrian paths would be on one side of the street, necessitating two crossings of Meadow or Charleston, depending on the travel direction, to complete their journey. The bike and pedestrian travel times for these alternatives are also summarized in Attachment B Private Property Impacts: The assessment of property impact reveals that the Partial Underpass for Churchill Avenue and the Underpass Alternative for Meadow Drive and Charleston Road have significant impact on private properties. The following provides a brief summary of overview of the property impacts associated with the various alternatives. Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 3  Packet Pg. 6 of 57  Churchill Avenue Based on the revised plans, Closure with Mitigation Option 2 will require some widening on both sides of Churchill. The road widening requires a partial acquisition of the two properties at the Alma/Churchill intersection. The road widening also results in the removal of trees (loss of the planting strip), and the loss of street parking for a length of approximately 300 feet east of Alma Street. Similarly, the Churchill Partial Underpass alternative will require widening of Kellogg Avenue (or Seale Avenue) to accommodate a pedestrian/bicycle ramp in the center of the street. This results in the removal of trees (loss of the planting strip), and the loss of street parking for a length of approximately 300 feet east of Alma Street on Kellogg or Seale. In addition, fifteen (15) front yard acquisitions, and driveway modifications are required to widen Alma Street and replace the planter strip from just north of Kellogg Avenue to just south of Coleridge Avenue. The maximum partial acquisition area is about 700 square feet, and the average partial acquisition area is approximately 300 square feet. Lastly, if the pedestrian/bicycle tunnel is built at Kellogg, then a partial acquisition of Palo Alto High School and a reconstruction of the bleachers would be required. Meadow Drive and Charleston Road: There have been no recent updates to the private property impacts for the Meadow- Charleston Trench Alternative. The Hybrid and Viaduct alternatives do not require any acquisitions; however, the elevated rail for these two alternatives presents a privacy concern for residential properties adjacent to the rail corridor between Loma Verde Avenue and Ferne Avenue with the greatest rail height occurring between Meadow and Charleston. The review of Underpass alternatives reveals that 12 residential properties at Meadow Drive, and 28 residential properties at Charleston Road are directly impacted by the project via partial acquisitions and construction easements. Tree removals are also required on most of these properties. For the Meadow Underpass, of the twelve (12) parcels, six (6) require front yard acquisitions and driveway modifications, one requires a side yard acquisition, and five (5) require back yard acquisitions. The maximum partial acquisition area is about 1,200 square feet and the average partial acquisition area is approximately 450 square feet. For Charleston, of the twenty-eight (28) parcels, nine (9) require front yard acquisitions and driveway modifications, two (2) require side yard acquisitions, and seventeen (17) require back yard acquisitions. The maximum partial acquisition area is about 3,300 square feet and the average partial acquisition area is approximately 1,000 square feet Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 4  Packet Pg. 7 of 57  At the committee's direction, staff has prepared the initial impact evaluation to perform review for the newly adopted City Council Summary of Evaluation Criteria. Upon selection of the preferred alternative, staff will inform property owners as directed by the Rail Committee and/or the City Council. Environmental Impacts: Based on the discussions and directions from the Rail Committee, additional factors are being considered for evaluation of Environmental impact. The Sea Level Rise, Heat Island effect, and Storm Drain impacts were analyzed to understand the impacts on various alternatives. The Consultant Memorandum summarizing their assessments are attached as Attachment C (Sea Level Rise Assessment) and Attachment D (Heat Island Effect and Storm Water Runoff Analyses) Seal Level Rise: In order to evaluate the environmental impacts due to sea level rise, two parameters were considered: projected sea level rise for the years 2050 and 2100 from the City of Palo Alto Sea Level Rise Vulnerability Assessment, and increased groundwater elevations resulting from sea level rise. •The Meadow-Charleston Trench alternative would be at some risk for the year 2100 sea level rise inundation. The remaining alternatives would not be exposed to sea level rise inundation. •The Meadow-Charleston Trench and the Meadow-Charleston Underpass would have project components within existing groundwater elevations. Increased groundwater elevation from sea level rise increases the potential for impacts to these alternatives from emergent groundwater. •While project components for the Meadow-Charleston Hybrid would not be within existing groundwater levels, the lowest proposed underpass elevation is close to current groundwater levels. Increased groundwater elevations from sea level rise might expose the underpass to emergent groundwater by 2100. Increased groundwater elevations from sea level rise can result in cracks, potholes, and sinkholes in the road. •The Churchill Closure with Mitigations, the Churchill Partial Underpass, and the Meadow-Charleston Viaduct are not anticipated to be affected by sea level rise or emergent groundwater. Heat Island Effect: A comparative analysis was made between the alternatives to evaluate their impacts related to heat island effects. In evaluating the heat island effects, consideration was given to the albedo of pavement areas and shaded areas cast by trees in vegetated areas. Albedo plays a pivotal role in the heat absorption and retention of pavements, influencing local microclimates and heat island effects. Albedo is a measure of the ability of an object to reflect solar radiation, where values range Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 5  Packet Pg. 8 of 57  between 0 (no sunlight reflected) to 1 (all sunlight is reflected). In general, lighter colored materials have higher albedo values and are more favorable because they reflect more sunlight, which can help cool the surrounding air. An evaluation of the existing project footprint was made by applying albedo values to the various surfaces. Similarly, albedo values were applied to the proposed infrastructure for each alternative and a comparison of the existing and proposed conditions (Attachment D – Heat Island Effect Comparative Analysis Report). The results are as follows: Churchill Avenue: For the Churchill Avenue Closure with Mitigation Option 1, an increase in the overall albedo value (more favorable) due to the extent of replacing existing asphalt with vegetated areas and construction of concrete pavement. This is the best performing alternative for those at Churchill Avenue, slightly better than Option 2. For the Churchill Closure with Mitigation (Option 2), a slight increase in the overall albedo value (more favorable) due to the extent of replacing existing asphalt with vegetated areas, and thus more shading west of the tracks. For the Churchill Partial Underpass, a negligible change was observed to the overall albedo values. The combination of replacing existing concrete with lighter albedo concrete and replacing existing asphalt with darker albedo asphalt pavements results in an expected neutral impact to heat island effects. Meadow Drive and Charleston Road: For the Trench and Viaduct alternative, the models observed a negligible change to the overall albedo value, however for the Hybrid alternative a slight decrease in the overall albedo value (less favorable) due to the extent of new asphalt pavement. Over time, the albedo of the asphalt will increase, and thus become more favorable. A slight increase in the overall albedo value (more favorable) due to the extent of replacing existing darker concrete with new (light-colored) concrete is also anticipated for the Underpass Alternatives at these crossings. Stormwater Treatment Stormwater management was assessed by calculating pavement areas and applying runoff coefficients to the various surfaces in existing conditions and for proposed infrastructure for each alternative. See Attachment D (Heat Island Effect and Storm Water Runoff Analyses. Changes to runoff coefficients were estimated as a measure of relative increases or decreases in runoff generation, as compared to existing conditions. Runoff coefficients are a parameter used to represent the proportion of precipitation that is expected to result in surface runoff, where values range Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 6  Packet Pg. 9 of 57  between 0 (complete infiltration) and 1 (all precipitation becomes direct runoff). The results are as follows: The results are as follows: Churchill Avenue: Churchill Closure with Mitigation option 1 resulted in negligible expected change to amount of stormwater runoff generated. However, for the Option 2, the introduction of new vegetated areas west of the tracks with higher perviousness results in some expected reduction in stormwater generation. For the Churchill Partial Underpass alternative, due to the large area of regraded (lowered) and replaced impervious surfaces the volume of runoff requiring treatment will increase substantially. Meadow Drive and Charleston Road: For Trench Alternative, the construction extents are limited to the existing railroad tracks. However, the more pervious existing railroad ballast will be replaced with a more impervious concrete surface along the length of the trench. As a result, this alternative is expected to have a relatively large increase in runoff generation, For Hybrid alternative, changes to land use and additional impervious areas (i.e., new underpass bridge) are minimal. The construction extents for Viaduct alternative are limited to the existing railroad tracks. If runoff from the raised viaduct can be directed to the underlying vegetated areas, no net increase in runoff generation is expected. The Underpass Alternative has a significant increase in the construction extents and changes to land use, especially with the conversion of existing vegetated areas to concrete and asphalt surfaces. Thus, a moderate increase to the amount of stormwater to be treated is expected. Visual Impacts A shadow analysis was performed for the Meadow-Charleston Hybrid and Viaduct alternatives that raises the rail profile. The analysis indicates that midday shadows are not significant as they would extend a maximum of about 15-20 feet from the edge of the viaduct structure. However, it was observed that in the early morning hours during the summer, shadows from the structure and train will be cast on nearby properties fronting the rail corridor on the west side of the tracks. And, in the late afternoon hours during the winter, shadows will be cast on Alma Street and the adjacent properties on the east side of the tracks. Costs A revision to the cost's comparative analysis is currently pending, taking into account utility impacts and long-term maintenance considerations. Although the cost update and matrix update are forthcoming; it's important to note that these impacts might be influenced by alterations to the alternatives following Caltrain's technical review. Staff will make necessary Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 7  Packet Pg. 10 of 57  adjustments to the costs as a clearer understanding of the updated alternatives becomes available. The analyses provided above provide information for updating the associated impact and improvements to the various updated categories of the Council Adopted Criteria. Therefore, staff request Rail Committee review of the updated Council Adopted Evaluation Matrix. FISCAL/RESOURCE IMPACT Revisions and edits to the Summary of Evaluation Matrix reflecting the study analyses are included within the approved scope of the consultant contract. STAKEHOLDER ENGAGEMENT The evaluation criteria provide an approach to reviewing alternatives under consideration in a systematic way. The updates to the previously adopted evaluation criteria were discussed at the Rail Committee’s regular meeting on March 29, 2023, and April 26, 2023, and City Council's regular meeting on June 12, 2023, where public comment was taken. Also, Rail Committee meetings are open to the public and therefore provide the community with opportunities to provide comments to the Rail Committee and the City. ENVIRONMENTAL REVIEW The proposed action is part of a planning study for a possible future action, which has not been approved, adopted, or funded and is therefore exempt from the California Environmental Quality Act (CEQA) in accordance with CEQA Guidelines Section 15262. The future decision to approve the construction of any one of the identified potential alternatives would be subject to CEQA and require the preparation of an environmental analysis. Environmental review and design for the grade separation project will be performed in the subsequent steps of the project development. ATTACHMENTS Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project Attachment C: Sea Level Rise Assessment Attachment D: Heat Island Effect and Storm Water Runoff Analyses APPROVED BY: Philip Kamhi, Chief Transportation Official Item 1 Item 1 Staff Report        Item 1: Staff Report Pg. 8  Packet Pg. 11 of 57  January 30, 2024 • Meadow-Charleston Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/1 of 5 ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement Meadow-Charleston Evaluation of City Council-Adopted Criteria Evaluation Criteria Trench Hybrid Viaduct Underpass A Facilitate movement across the corridor for all modes of transportation Meadow Drive and Charleston Road will be grade separated from the railroad for all modes and will remain open. Meadow Drive and Charleston Road will be grade separated from the railroad for all modes and will remain open. Meadow Drive and Charleston Road will be grade separated from the railroad for all modes and will remain open. Viaduct provides opportunities for additional crossings for all modes. East/West (through) traffic on Meadow Drive and Charleston Road will be grade separated from the railroad and Alma Street for all modes. Turning movements from Meadow Drive to southbound Alma Street will be prohibited. Turning movements from northbound Alma Street will require a U-turn at Alma Village Circle. All turning movements on Charleston Road to/from Alma Street will be permitted; however, some movements will be facilitated via a roundabout approximately 600 feet east of Alma Street, resulting in longer routes for all modes compared to the Trench, Hybrid, and Viaduct alternatives. B Reduce delay and congestion for vehicular traffic at rail crossings With construction of the grade separation, the railroad crossing gates and warning lights at Meadow Drive and Charleston Road will be removed. Thus, the traffic will not be interrupted by the railroad crossing gates. With construction of the grade separation, the railroad crossing gates and warning lights at Meadow Drive and Charleston Road will be removed. Thus, the traffic will not be interrupted by the railroad crossing gates. With construction of the grade separation, the railroad crossing gates and warning lights at Meadow Drive and Charleston Road will be removed. Thus, the traffic will not be interrupted by the railroad crossing gates. With construction of the grade separation, the railroad crossing gates and warning lights at Meadow Drive and Charleston Road will be removed. Thus, the traffic will not be interrupted by the railroad crossing gates. Pedestrian and cyclist mode separation will also help reduce intersection congestion. Some turning movements will be prohibited at the Alma/Meadow intersection and thus would use the Charleston Road intersection or the new signal at Alma Village Circle. At the Alma/Charleston intersection, some turning movements will increase overall delays due to the circuitous nature of the movements, as vehicles would need to use the Charleston roundabout and return to the Alma intersection to complete the movements (e.g. eastbound left-turns to Alma, northbound left-turns and southbound right-turns to Charleston). C Provide clear, safe routes for pedestrians and cyclists crossing the rail corridor, separate from vehicles Pedestrians/cyclists will be separated from train traffic. Conflicts between pedestrians/cyclists and motor vehicles will remain at the Alma intersections. Bike lanes will be added to Meadow Drive and Charleston Road intersections. Additional pedestrian/cyclist separations routes can be explored in the next phase of design. Pedestrians/cyclists will be separated from train traffic. Conflicts between pedestrians/cyclists and motor vehicles will remain at the Alma intersections. Bike lanes will be added to Meadow Drive and Charleston Road intersections. Additional pedestrian/cyclist separations routes can be explored in the next phase of design. Pedestrians/cyclists will be separated from train traffic. Conflicts between pedestrians/cyclists and motor vehicles will remain at the Alma intersections. Bike lanes will be added to Meadow Drive and Charleston Road intersections. Additional pedestrian/cyclist separations routes can be explored in the next phase of design. Pedestrians and cyclists traveling east/ west will be completely separated from train and vehicular traffic on Alma Street. Full pedestrian and cyclist movement is maintained. Pedestrians and cyclists will have more circuitous routes traveling east/west across the corridor because the pedestrian/bike path is located on one side of the street only: on the south side of Meadow Drive and on the north side of Charleston Road. For example, cyclists traveling eastbound on Charleston Road near Ruthelma Street will have to cross Charleston Road to get onto the north side of the road, then cross Charleston Road again at the roundabout near Mumford Place to get back onto the right/ south side of the road. The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 9  Packet Pg. 12 of 57  January 30, 2024 • Meadow-Charleston Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/2 of 5 ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement Meadow-Charleston Evaluation of City Council-Adopted Criteria Evaluation Criteria Trench Hybrid Viaduct Underpass D Support continued rail operations and Caltrain service improvements A temporary railroad track will be required, and a crossover track located north of the San Antonio Caltrain Station will be relocated. With the pump stations, there will be potential risks to train operations from flooding. A temporary railroad track will be required, and a crossover track located north of the San Antonio Caltrain Station will be relocated. New railroad tracks can be built without a temporary track, and a crossover track located north of the San Antonio Caltrain Station will be relocated. A temporary railroad track is likely to be required unless an alternate construction methodology and sequencing is acceptable to Caltrain. E Finance with feasible funding sources (order of magnitude cost) The trench will require greater levels of local funding in the form of fees, taxes or special assessments, the feasibility of which are still being studied in the context of overall citywide infrastructure funding needs. The hybrid would require lower levels of local funding, with a substantial portion of capital costs covered by Regional, State and Federal sources. The viaduct would require substantial local funding resources more than the hybrid alternative, but less than the trench and tunnel alternatives. The underpass will require substantial local funding resources more than the hybrid alternative, but less than the trench and tunnel alternatives. F Minimize right-of-way acquisition (Private property only) Subsurface acquisition will be required for the ground anchors for the trench retaining walls and private properties will be required for creek diversion pump station. No acquisition of private properties is required; however, driveway modifications will be required.No acquisition of private properties is required. Five (5) full private property acquisitions are required in multiple locations (two at Meadow Drive and three at Charleston Road). Multiple driveway modifications will be also required. Partial (sliver) acquisition of residential properties and removal of trees will be required at various locations and summarized below: At Meadow Drive: • Six (6) front yard acquisitions on both sides of Meadow between 2nd Street and Park Boulevard. • One (1) side yard acquisition on the north side of Meadow, just west of Emerson Street. • Five (5) backyard acquisitions on the south side of Meadow between Alma Street and Emerson Street. At Charleston Road: • On both sides of Charleston between Ruthelma Avenue and Park Boulevard. Seven (7) front yard acquisitions; two (2) on the north side, five (5) on the south side of Charleston. • One side yard acquisition on the south side of Charleston between Park Boulevard and the railroad tracks. • Eight (8) property acquisitions on both sides of Charleston between Alma St and Wright Place; six (6) backyard acquisitions on the north side of Charleston, and two (2) front yard acquisitions on the south side of Charleston (closest to Alma). • Six (6) backyard acquisitions on the north side of Charleston between Wright Place and Mumford Place. • Six (6) property acquisitions along Alma Street between Charleston Road and Ely Place; five (5) backyard acquisitions, and one side yard acquisition (closest to Ely Place). The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 10  Packet Pg. 13 of 57  January 30, 2024 • Meadow-Charleston Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/3 of 5 ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement Meadow-Charleston Evaluation of City Council-Adopted Criteria Evaluation Criteria Trench Hybrid Viaduct Underpass G1 Reduce rail noise and vibration Train horn noise and warning bells will be eliminated with the replacement of the at-grade crossings with grade separations. Utilizing EMU trains instead of diesel locomotives will also reduce noise. Trains operating in trench will reduce noise in neighborhoods. Acoustically treated trench walls will eliminate acoustical reflections. There would be a slight reduction to vibration levels at nearby receptors. Train horn noise and warning bells will be eliminated with the replacement of the at-grade crossings with grade separations. Utilizing EMU trains instead of diesel engines will also reduce noise. Six-foot high parapet sound barriers will help reduce propulsion and wheel/rail noise. There would be a slight reduction to vibration levels at nearby receptors. Train horn noise and warning bells will be eliminated with the replacement of the at-grade crossings with grade separations. Utilizing EMU trains instead of diesel engines will also reduce noise. Six-foot high parapet sound barriers will help reduce propulsion and wheel/rail noise. There would be significant reduction to vibration levels at nearby receptors. Train horn noise and warning bells will be eliminated by the replacement of the at-grade crossings with grade separations. Utilizing EMU trains rather than diesel engines will also reduce noise. Modern rail bridge design will reduce excess structural noise. Sound barriers will also help to reduce propulsion and wheel/rail noise. There would be little to no change to vibration levels at nearby receptors. An optional 6-foot high noise barrier near the tracks and on the overpass structure could significantly reduce wheel/rail and propulsion noise. G2 Sea Level Rise Susceptibility The low point of the track profile (Elevation 4 feet) for the trench alternative would be close to the projected sea level rise inundation zone for the year 2100 (a sea level rise of 3.42 feet ). The trench’s track profile is below the estimated groundwater (approximately between Elevation 20 and 25) for about 4,000 feet along the track. Increased groundwater elevations from sea level rise would further expose the trench to emergent groundwater by 2100. A pump station is proposed, but groundwater depletion and additional studies would be needed to further assess the feasibility of this alternative. The hybrid alternative would be outside of the projected sea level rise inundation zone for the year 2100. The low point of the proposed roadway for the Hybrid at Meadow (Elevation 30 feet) is about 9 feet higher than current groundwater (Elevation 21). The low point of the proposed roadway for the Hybrid at Charleston (Elevation 34 feet) is about 12 feet higher than current groundwater (Elevation 22 ). Increased groundwater elevations from sea level rise can damage a roadway from below, increasing the likelihood of cracks, potholes, and sinkholes. The viaduct structure is not anticipated to be affected by sea level rise or emergent groundwater.The underpass alternative would be outside of the projected sea level rise inundation zone for the year 2100. The low point of the proposed roadway for the underpass at Meadow (Elevation 12 feet) is about 9 feet below current groundwater (Elevation 21). The low point of the proposed roadway for the underpass at Charleston (Elevation 16 feet) is about 6 feet below current groundwater (Elevation 22). Increased groundwater elevations from sea level rise would further expose the underpass alternative to emergent groundwater by 2100. G3 Heat Island Effect Construction extents are limited to the existing railroad tracks. Negligible changes to heat island effects due to minimal changes to land use. The replacement of asphalt pavement for roadway grading results in some impact to heat island effects, because newer asphalt pavement surfaces have lower albedo ratings that will increase with age. Lower albedo ratings are less favorable because more light is absorbed, which heats up the surrounding air. Construction extents are limited to the existing railroad tracks. Negligible changes to heat island effects due to minimal changes to land use. As the alternative with the largest construction extents, the replacement of existing darker concrete with new concrete with higher albedo ratings results in some expected improvement to heat island effects. Higher albedo ratings are more favorable because more light is reflected, which can help cool the surrounding air. G4 Stormwater Treatment Construction extents are limited to the existing railroad tracks. Significant changes to the amount of stormwater runoff generated from project area expected, due to changes in land use from existing railroad ballast to significantly more impervious concrete surfaces. Changes to land use and additional impervious areas (i.e., new underpass bridge) are minimal. Construction extents are limited to the existing railroad tracks. With the assumption that runoff from the raised viaduct can all be directed to the underlying vegetated areas, no net increase in runoff generation is expected. As the alternative with the largest construction extents and changes to land use, especially with the conversion of existing vegetated areas to concrete and asphalt surfaces, a moderate impact to the amount of stormwater to be treated is expected. H Maintain access to neighborhoods, parks, and schools along the corridor, while reducing regional traffic on neighborhood streets No diversion of regional traffic with construction of grade separations. No diversion of regional traffic with construction of grade separations. No diversion of regional traffic with construction of grade separations. Regional traffic will be diverted due to the restricted turning movements; however, travel in all directions will be possible, but may require a longer route and take more time. Turning movements at Ely Place will be limited to right turns on northbound Alma Street only. Pedestrian and cyclist access will improve due to mode separation. The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 11  Packet Pg. 14 of 57  January 30, 2024 • Meadow-Charleston Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/4 of 5 ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement Meadow-Charleston Evaluation of Engineering Challenges Engineering Challenges Trench Hybrid Viaduct Underpass L Creek/Drainage Impacts • Requires diversion of Adobe and Barron creeks resulting in the need for pump stations. • Numerous regulatory agency approvals required for creek diversion. • Pump stations also required to dewater the trench. • Increased risk of flooding due to pump stations. • Pump stations required for lowered roadways. • Increased risk of flooding due to pump stations. • No significant creek or drainage impacts.• Pump station required for lowered roadways. • Increased risk of flooding due to pump station. Meadow-Charleston Evaluation of City Council-Adopted Criteria Evaluation Criteria Trench Hybrid Viaduct Underpass I Minimize visual changes along the corridor Railroad tracks will be below grade with high fencing at grade. Landscaping options will be limited to plants with shallow roots in areas where ground anchors are required for the trench retaining walls. Railroad tracks will be approximately 15 feet above grade. Landscaping with trees will be incorporated for screening where feasible. During the winter, late afternoon (after 3 pm) shadows are significant on the east side of the structure as they extend to the west-facing, residential properties on the east side of Alma Street. Railroad tracks will be approximately 20 feet above grade. Landscaping with trees will be incorporated for screening where feasible. Shadows from the viaduct structure extend about 15 feet from each side of the structure in the mid-morning (9 am) and mid-afternoon (3 pm) hours during the summer solstice. During the winter, late afternoon (after 3 pm) shadows are significant on the east side of the structure as they extend to the west-facing, residential properties on the east side of Alma Street. Railroad tracks will remain at-grade. On Charleston Road, removal of the planting strip on both sides of the road will be required along with the planting strip on the east side of Alma Street between Charleston Road and Ely Place. J Minimize disruption and duration of construction Extended road closures at Meadow Drive and Charleston Road are required. Construction would last for approximately 6 years. Extended lane reductions at Alma Street, Meadow Drive, and Charleston Road will be required. Construction would last for approximately 4 years. The viaduct will have minimal road closures (nights/weekends only). Construction would last for approximately 2 years. Lane reductions and temporary closures (nights/weekends only) on Alma Street, a closure of Meadow Drive between Emerson Street and Park Boulevard, and a closure of Charleston Road between Alma Street and Park Boulevard will be required for the majority of construction. The total duration of construction will be approximately 3.5 to 4 years; however the durations are subject to change depending on the construction methodologies used. Order of magnitude cost $800M to 950M*$190M to $230M*$400M to 500M*$340M to $420M* * Total Preliminary Construction Cost for infrastructure of both railroad crossings in 2018 dollars, and includes escalation to 2025 (Subject to Change). The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 12  Packet Pg. 15 of 57  January 30, 2024 • Meadow-Charleston Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/5 of 5 ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement Meadow-Charleston Evaluation of Engineering Challenges Engineering Challenges Trench Hybrid Viaduct Underpass M Long-Term Maintenance Increased maintenance costs due to: • Pump stations for creek diversions. • Pump stations for trench dewatering. • Below ground railroad alignment. Increased maintenance costs due to: • Pump stations for trench dewatering. • Above ground railroad alignment with embankments and undercrossing structures. Increased maintenance costs due to: • Above ground railroad alignment with embankments and viaduct structures. Increased maintenance cost due to: • Pump stations for underpass dewatering. • Above ground structures for both road and rail. N Utility Relocations • Major utility relocations for lowered railroad.• Moderate amount of utility relocations for utility relocations for lowered roadways.• Some utility relocations required.• Major utility relocation due to the fully lowered roadway. O Railroad Operations Impacts during Construction • Temporary track (i.e., shoofly) is required.• Temporary track (i.e., shoofly) is required, but a bit shorter than the trench shoofly.• No temporary track (i.e., shoofly) required.• Temporary track (i.e., shoofly) likely required unless an alternate construction methodology and sequencing is acceptable to Caltrain. P Local Street Circulation Impacts during Construction • Removal of right turn lanes on Alma Street at Meadow Drive and Charleston Road; however, traffic will still be able to flow as needed despite lane reduction. • Closes Meadow Drive while Charleston Road roadway bridges are constructed and visa versa. • Removal of right turn lanes on Alma Street at Meadow Drive and Charleston Road; however, traffic will still be able to flow as needed despite lane reduction. • Alma Street, Charleston Road, and Meadow Drive reduced to 2 lanes. • Reduced lane widths on Alma Street, north of Meadow Drive and south of Charleston Road. • Possible night time closures of Meadow Drive and Charleston Road. • Lane reduction on Alma Street during construction of the shoofly and bridge. • Closure of Meadow Drive and Charleston Road throughout excavation and construction of the undercrossing and related features. Q Caltrain right-of-way Impact (Probability of approval by Caltrain of permanent encroachment inside Caltrain’s right-of-way is unknown at this time). Permanent encroachment inside Caltrain’s right-of-way is required to accommodate pump station(s). No permanent encroachment inside Caltrain’s right-of-way is required.No permanent encroachment inside Caltrain’s right-of-way is required. However, options of a linear park or dual use under the viaduct would require Caltrain approval. No permanent encroachment inside Caltrain’s right-of-way is required. R Caltrain Design Exceptions Needed 2% grade on track required. Maximum grade allowed by Caltrain is 1%.Temporary vertical clearance of 12 feet at undercrossing structures during construction. Minimum vertical clearance allowed by Caltrain is 15.5 feet. 1.4% grade on track required. Maximum grade allowed by Caltrain is 1%.No Caltrain design exceptions required. The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 13  Packet Pg. 16 of 57  ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement 1 of 3January 30, 2024 • Churchill Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/ Churchill Evaluation of City Council-Adopted Criteria Evaluation Criteria Closure with Mitigations Partial Underpass A Facilitate movement across the corridor for all modes of transportation Churchill Avenue will be closed to vehicles at the railroad tracks. Pedestrians and cyclists will be grade separated from the railroad in Option 1. For Option 2, pedestrians and cyclists will be grade separated from the railroad and vehicle traffic on Alma Street. Churchill Avenue will be grade separated from the railroad for all modes and will remain open. Through traffic on Churchill Avenue is no longer possible, and some traffic will have to take alternate routes. Pedestrian/bike (only) traffic will be grade separated from the railroad and vehicle traffic on Alma Street via an undercrossing at Kellogg Avenue or Seale Avenue. B Reduce delay and congestion for vehicular traffic at rail crossings With closure of Churchill Avenue, traffic will be diverted to Embarcadero and Page Mill Road and thus, nearby intersections will be impacted; however, operational improvements are proposed at the Embarcadero/Kingsley/Alma intersection, El Camino Real intersections at Embarcadero Road and Page Mill Road and Alma/Oregon Expressway interchange that would mitigate the traffic impacts. With construction of the grade separation, the railroad crossing gates and warning lights at Churchill Avenue will be removed. Thus, the traffic will not be interrupted by the railroad crossing gates. Pedestrian undercrossing at Kellogg Avenue or Seale Avenue will also help reduce intersection congestion. C Provide clear, safe routes for pedestrians and cyclists crossing the rail corridor, separate from vehicles Pedestrians/cyclists will be separated from train traffic and vehicles.Pedestrians and cyclists will be completely separated from train and vehicular traffic. Full pedestrian and cyclist movement is maintained with a new undercrossing at Kellogg Avenue or Seale Avenue. D Support continued rail operations and Caltrain service improvements A temporary railroad track will not be required.A temporary railroad track is likely to be required unless an alternate construction methodology and sequencing is acceptable to Caltrain. E Finance with feasible funding sources (Order of magnitude cost) The closure would require the lowest levels of local funding, with a substantial portion of capital costs covered by Regional, State and Federal sources. The underpasses would require lower levels of local funding, with a substantial portion of capital costs covered by Regional, State, and Federal sources. F Minimize right-of-way acquisition (Private property only) No acquisition of private properties is required; however, there will be impacts to the Palo Alto High School property. Loss of street parking loss and removal of the planter strip on both sides of Churchill Avenue, east of Alma Street, will be required for the pedestrian/bike undercrossing (Option 2 only). Driveway modifications, removal and relocation of planter strips, and and partial (sliver) acquisitions of residential properties will be required due to widening of Alma Street between Kellogg Avenue and Coleridge Avenue. Some (sliver) acquisition of the high school and/or residential property fronting Churchill Avenue on the west side of the tracks will be required. For the pedestrian undercrossing at Kellogg Avenue (or Seale Avenue), loss of street parking and removal of the planter strip on both sides of Kellogg Avenue (or Seale) will be required for approximately 250-300 feet from Alma Street. G1 Reduce rail noise and vibration Train horn noise and warning bells will be eliminated with the removal of the at-grade crossings with roadway closure. Utilizing EMU trains instead of diesel engines will also reduce noise. There would be no change to vibration levels at nearby receptors. An optional 6-foot high noise barrier near the tracks could significantly reduce wheel/rail and propulsion noise. Train horn noise and warning bells will be eliminated by the replacement of the at-grade crossings with grade separations. Utilizing EMU trains rather than diesel engines will also reduce noise and some road noise would be reduced. Modern rail bridge design will reduce excess structural noise. There would be little to no change to vibration levels at nearby receptors. An optional 6-foot high noise barrier near the tracks and on the overpass structure could significantly reduce wheel/rail and propulsion noise. G2 Sea Level Rise Susceptibility The closure alternative would be outside of the projected sea level rise inundation zone for the year 2100. The lowest pedestrian underpass elevations (27 feet at Kellogg, and 20 feet at Seale Avenue) would still be well above current groundwater levels (Elevation 8-11 feet). The underpass alternative would be outside of the projected sea level rise inundation zone for the year 2100. The lowest elevations (27 feet for the pedestrian underpass at Kellogg, 25 feet for the roadway underpass at Churchill and 20 feet for the pedestrian underpass at Seale Avenue) would still be well above current groundwater levels (Elevation 8-11 feet). This alternative is not anticipated to be affected by sea level rise or emergent groundwater. G3 Heat Island Effect The introduction of new vegetated areas, with higher albedo ratings than asphalt surfaces and increased provision of shading, southwest of the Alma St & Churchill Ave intersection results in an expected improvement to heat island effects. Higher albedo ratings are more favorable because more light is reflected, which can help cool the surrounding air. The combination of replacing existing concrete with lighter albedo concrete and replacing existing asphalt with darker albedo asphalt pavements results in an expected neutral impact to heat island effects. G4 Stormwater Treatment The introduction of new vegetated areas, with lower runoff coefficients and higher expected perviousness, southwest of the Alma St & Churchill Ave intersection results in some expected reduction in stormwater generation. Due to the large area of regraded (lowered) and replaced impervious surfaces the volume of runoff requiring treatment will increase substantially as compared to existing conditions. The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 14  Packet Pg. 17 of 57  ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement Churchill Evaluation of City Council-Adopted Criteria Evaluation Criteria Closure with Mitigations Partial Underpass H Maintain access to neighborhoods, parks, and schools along the corridor, while reducing regional traffic on neighborhood streets Vehicle access will be diverted and resultant regional traffic will be mitigated. Pedestrian and cyclist access will improve to mode separation.Regional traffic will be diverted due to the restricted turning movements. Pedestrian and cyclist access will improve due to mode separation. I Minimize visual changes along the corridor Railroad tracks remain at existing grade. Residual roadway areas from the closure provide opportunities for landscaping at Churchill between Mariposa Avenue and the tracks. Some tree removals will be required on both sides of Churchill for a length of approximately 250-300 feet east of Alma Street to accommodate a ped/bike ramp down the center of Churchill (Option 2 only). The railroad tracks and the northbound lanes of Alma Street will remain at-grade, and the east side of Churchill Avenue will remain unchanged. Mature trees and overhead power poles within the Alma Street planting strip, from just north of Kellogg Avenue to just south of Coleridge Avenue, will be removed. Landscaping restoration is limited due to space constraints. J Minimize disruption and duration of construction The closure will have minimal road closures (nights/weekends only). Construction would last for approximately 2 years. Closure of Churchill Avenue between Alma Street and Mariposa Avenue will be required for the majority of construction. Alma Street will be one-way northbound for approximately 6+ months. Total duration of construction will be approximately 2.5 to 3 years; however the durations are subject to change depending on the construction methodologies used. Order of magnitude cost $50M to $65M*$160M to $200M* 2 of 3January 30, 2024 • Churchill Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/ Churchill Evaluation of Engineering Challenges Engineering Challenges Closure with Mitigations Partial Underpass L Creek/Drainage Impacts • Pump station required for lowered pedestrian/bike undercrossing. • Increased risk of flooding with pump stations. • Relocation of the pump house at Embarcadero Road required to accommodate widening of Alma Street. • Pump station required for lowered roadways. • Increased risk of flooding due to pump station. M Long-Term Maintenance Increased maintenance costs due to: • Pump stations for undercrossing dewatering. Increased maintenance cost due to: • Pump stations for underpass dewatering. • Above ground structures for both road and rail. N Utility Relocations • Potential utility relocations in Alma Street and Churchill Avenue for pedestrian/bike undercrossing. • Minor utility relocations for Embarcadero Road/Alma Street improvements. • Major utility relocations for lowered roadways. O Railroad Operations Impacts during Construction • No temporary track (i.e., shoofly) required, only single tracking during nights and weekends.• Temporary track (i.e., shoofly) likely required unless alternate construction methodology and sequencing is acceptable to Caltrain. * Total Preliminary Construction Cost for infrastructure of the railroad crossing in 2018 dollars, and includes escalation to 2025 (Subject to Change). The color of the matrix is comparative between each alternative at this location. Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 15  Packet Pg. 18 of 57  ImprovementImpact Most Impact Some Impact Some Improvement Moderate Impact Neutral (No Impact or Improvement) Moderate Improvement Most Improvement The color of the matrix is comparative between each alternative at this location. 3 of 3 Churchill Evaluation of Engineering Challenges Engineering Challenges Closure with Mitigations Partial Underpass P Local Street Circulation Impacts during Construction • Path along Palo Alto High School will temporarily be impacted during construction. • Temporary night and weekend closure of lanes on Churchill Avenue, Alma Street, Embarcadero Road, El Camino Real, and Oregon Expressway. • Lane reduction on Alma Street during construction of the shoofly and bridge. • Likely closure of Churchill Avenue throughout the excavation and construction of the undercrossing and related features. • Likely closure of Kellogg Avenue for the duration of the pedestrian underpass construction; driveway access from one direction only. Q Caltrain right-of-way Impact (Probability of approval by Caltrain of permanent encroachment inside Caltrain’s right-of-way is unknown at this time). Requires permanent longitudinal encroachment inside Caltrain’s right-of-way for the pedestrian/bike ramps for undercrossing Option 1. Requires permanent longitudinal encroachment inside Caltrain’s right-of-way for the pedestrian/bike ramps (to the undercrossing at Kellogg Avenue) and for the lanes/shoulders for southbound Alma Street. R Caltrain Design Exceptions Needed None required.No Caltrain design exceptions needed. January 30, 2024 • Churchill Summary of Evaluation • For more renderings, plans and animations visit: https://connectingpaloalto.com/renderings-plans-and-animations/ Summary of Evaluation Item 1 Attachment A: Summary of Evaluation Matrix based on Updated Council Adopted Criteria        Item 1: Staff Report Pg. 16  Packet Pg. 19 of 57  Memorandum Date: January 16, 2024 To: Mr. Ripon Bhatia, City of Palo Alto From: Gary Black, Trisha Dudala Subject: Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project Hexagon Transportation Consultants, Inc. completed an evaluation of east/west connectivity across Alma Street and the Caltrain tracks. The study evaluated travel time/delay for motor vehicles and travel time/safety for bicycles and pedestrians. Grade separations were evaluated at Churchill Avenue, Meadow Drive, and Charleston Road. The two alternatives that are being considered for the Churchill crossing are closure and a partial underpass. The partial underpass would allow turns from Alma to Churchill under the railroad but would not allow through traffic on Churchill Avenue. Both alternatives would include a bike/pedestrian underpass. Either alternative would improve bicycle and pedestrian safety. Motor vehicle delays would be reduced for the movements that would be allowed, but some existing movements would be cut off. Three alternatives are being considered for the Meadow and Charleston railroad crossings: Trench, Hybrid and Underpass. The trench and hybrid alternatives would depress the railroad, and Meadow and Charleston would pass over. The traffic signals at Alma Street would remain, so there would be delays for motor vehicles, bicycles, and pedestrians at red lights. However, delays at the railroad crossings would be eliminated. In the Underpass alternative, Meadow and Charleston would pass under both Alma Street and the railroad. Overall, the Underpass alternative would result in lower vehicular delays compared to the Trench/Hybrid alternatives. However, some vehicular movements would have increased delays. The increased delays are due to the circuitous nature of the movements, as vehicles would need to use the Alma Village Circle signal or the Charleston roundabout to complete their maneuver. Pedestrians and bicyclists on Meadow and Charleston would not need to interface with motor vehicles with the Underpass option. However, the proposed bike/pedestrian paths would be on only one side of the street, so, depending on the travel direction, they would need to cross Meadow or Charleston twice to complete their journey. The analysis is presented in detail below. The following grade separation alternatives were analyzed. A rendering of these alternatives is included in the appendix. Churchill Alternatives • Churchill Grade Separation * • Churchill Partial Underpass • Churchill Closure (Option 1) Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 17  Packet Pg. 20 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 2 • Churchill Closure (Option 2) *The “Grade Separation” alternative, shown as Viaduct in the tables is not being considered by the city but was analyzed for comparison purposes with the other alternatives still being considered by the City. Meadow - Charleston Alternatives • Meadow – Charleston Trench • Meadow – Charleston Hybrid • Meadow – Charleson Viaduct * • Meadow – Charleston Underpass *The “Viaduct” option is no longer under consideration. Intersection Delays Intersection delays for the grade separation alternatives were analyzed using future year 2030 intersection turning movement volumes at Churchill Avenue, Meadow Drive and Charleston Road with Alma Street. The 2030 intersection delays are based on the Churchill, Meadow, and Charleston Grade Separation Traffic Analysis memorandum dated August 13, 2020 prepared by Hexagon. These volumes were based on the 2030 forecasts presented in the Draft Churchill Closure report by TJKM. The intersection turning movement delays are based on the Synchro/SimTraffic analysis that was conducted for the Churchill, Meadow, and Charleston Grade Separation Traffic Analysis. Tables 1 – 3 provide a comparison of the 2030 intersection delays for the grade separation alternatives for each of the twelve turning movements at the Alma/Churchill, Alma/Meadow, and Alma/Charleston intersections. In the tables, green indicates reduced delays and orange indicates increased delays compared to the Viaduct alternative. At the Alma/Churchill intersection, the Churchill Closure and Partial Underpass alternatives show reduced delays compared to the Viaduct alternative for nearly all movements (see Table 1). However, many turning movements would no longer be possible with Churchill closure, and some movements would be precluded with the Partial Underpass. At the Alma/Meadow intersection, the Underpass alternative shows reduced delays compared to the Hybrid/Trench alternative for most movements (see Table 2). However, some movements would not be possible with the Underpass (eastbound to southbound right turn and westbound to southbound left turn), and that traffic would need to use the Charleston intersection instead. The northbound rights from Alma to Meadow Drive would be facilitated via the signal at Alma/Alma Village Circle intersection. This traffic would make a U-turn at the Alma Village Circle signal and then make a left-turn at the Alma southbound off-ramp to Meadow signal to travel eastbound on Meadow Drive, resulting in slightly longer delays due to the circuitous nature of this movement. At the Alma/Charleston intersection, the Underpass alternative shows increased delays compared to the Hybrid/Trench alternatives for some movements, including eastbound left turns, westbound left turns, westbound right turns, and southbound right turns during the AM peak hour and the northbound through movement during the PM peak hour (see Table 3). The increased delays are due to the circuitous nature of the movements, as vehicles would need to use the neighboring roundabout and return to the intersection in order to complete certain turning movements. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 18  Packet Pg. 21 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 3 Table 1 Intersection Movement Delays at Alma/Churchill Alma/Churchill EBL AM 64.6 N/A 18.8 PM 115.4 N/A 31 EBT AM 62.6 N/A N/A PM 117.2 N/A N/A EBR AM 12.2 N/A 6.2 PM 64.9 N/A 17.3 WBL AM 63.0 40.8 N/A PM 72.0 69.3 N/A WBT AM N/A N/A N/A PM 69.0 N/A N/A WBR AM 47.0 24.0 21.2 PM 53.0 45.3 10.6 NBL AM 114.7 N/A 24 PM 99.2 N/A 44.9 NBT AM 35.3 27.3 0.7 PM 35.2 34.6 3.5 NBR AM 42.4 38.1 1.6 PM 35.0 35.0 0.7 SBL AM 84.5 70.7 N/A PM 154.7 124.0 N/A SBT AM 47.0 13.4 14.4 PM 63.1 22.9 26.4 SBR AM 26.4 N/A 10 PM 50.3 N/A 22.6 Notes:- indicates reduced delays compared to the Viaduct alternative. N/A - Movement not allowed. Partial Underpass 2030 Delays (seconds / vehicle) Intersection Movement Peak Hour Churchill ClosureViaduct Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 19  Packet Pg. 22 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 4 Table 2 Intersection Movement Delays at Alma/Meadow Alma/Meadow EBL AM 64.1 8.1 PM 43.4 8.3 EBT AM 73.7 14.1 PM 45.5 16.5 EBR AM 18.0 N/A PM 29.2 N/A WBL AM 85.6 N/A PM 43.5 N/A WBT AM 89.7 15.3 PM 46.6 13.6 WBR AM 15.9 6.5 PM 27.8 7.6 NBL AM 118.7 41.3 PM 126.1 51.8 NBT AM 50.0 0.0 PM 78.9 0.0 NBR AM 53.8 55.3 PM 78.5 80.9 SBL AM 109.6 8.8 PM 443.9 10.0 SBT AM 37.4 0.0 PM 463.7 0.0 SBR AM 19.3 6.1 PM 463.1 7.4 Notes:- indicates reduced delays compared to the Hybrid/Trench alternatives. indicates increased delays compared to the Hybrid/Trench alternatives. N/A - Movement not allowed. 2030 Delays (seconds / vehicle) Intersection Movement Peak Hour UnderpassHybrid/ Trench/ Viaduct Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 20  Packet Pg. 23 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 5 Table 3 Intersection Movement Delays at Alma/Charleston Alma/Charleston EBL AM 47.1 149.1 PM 437.3 110.0 EBT AM 52.7 2.0 PM 420.1 5.9 EBR AM 45.6 0.9 PM 494.8 3.6 WBL AM 55.5 98.6 PM 74.8 54.5 WBT AM 51.1 0.9 PM 75.9 1.0 WBR AM 33.5 78.7 PM 61.3 39.6 NBL AM 179.4 80.8 PM 111.2 78.7 NBT AM 195.1 37.5 PM 47.8 50.5 NBR AM 177.3 9.7 PM 47.8 7.6 SBL AM 91.9 11.9 PM 303.4 17.6 SBT AM 52.3 17.2 PM 264.5 27.5 SBR AM 35.7 84.8 PM 235.1 90.5 Notes:- indicates reduced delays compared to the Hybrid/Trench alternatives. indicates increased delays compared to the Hybrid/Trench alternatives. 2030 Delays (seconds / vehicle) Intersection Movement Peak Hour Underpass (With Roundabout) Hybrid/ Trench/ Viaduct Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 21  Packet Pg. 24 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 6 Induced Travel Although the grade separation alternatives show reduced delays and improvements in travel times across the east/west streets, none of the grade separation alternatives are likely to induce travel demand. Induced travel is defined as the increase in vehicle travel that occurs because of capacity expansion, which enables more trips and longer distance trips in a given amount of time due to increased travel speed. Alma/Churchill Grade Separation Alternatives The two alternatives that are being considered are the Churchill Closure and Partial Underpass alternatives. The Viaduct alternative is not being considered for further evaluation so vehicular and cyclist/pedestrian delays under this alternative are provided only for comparison purposes. For the Churchill closure option, Churchill Avenue would be closed off, west of the Caltrain tracks, and Churchill Avenue would no longer provide an east-west connection for vehicles across Alma Street. Under the partial grade separation alternative, access to Alma Street would be maintained by keeping Churchill Avenue partially open via a modified underpass. However, no through traffic would be possible on Churchill Avenue across Alma Street. Therefore, there would be no induced travel under either alternative. Alma/Charleston and Alma/Meadow Grade Separation Alternatives The alternatives that are being considered are the Hybrid/Trench alternatives and the Underpass Alternative. Under the Hybrid/Trench alternatives, the railroad would be grade separated, which would eliminate the traffic signal at the railroad tracks. However, the analysis shows that with future traffic volumes, vehicular delays at the Alma/Charleston intersection and Alma/Meadow intersection under the Hybrid/Trench alternatives would be similar or higher compared to existing traffic delays at these intersections (based on the Churchill, Meadow, and Charleson Grade Separation Traffic Analysis memorandum dated August 13, 2020 prepared by Hexagon). Therefore, it is unlikely that the Hybrid/Trench alternatives would induce travel demand along Charleston Road or Meadow Drive. For the Underpass alternative, east/west through traffic on Meadow Drive and Charleston Road would be separated from Alma Street and thus would have lower delays compared to existing conditions. However, the improvement in travel time generally would be one minute or less, which is negligible compared to typical trip lengths of 10 – 30 minutes. Also, as some movement connections would have increased travel times, the underpass alternative is not likely to induce vehicular travel. However, the underpass alternative would cause some traffic on Meadow Drive to divert onto Charleston Road (less than 150 vehicles during the peak commute hours) as some vehicular turning movements would not be feasible at the Alma/Meadow intersection. The vehicular movement delays presented in Table 3 for the Alma/Charleston intersection reflect the diverted volume from Meadow Drive to Charleston Road. Bicycle and Pedestrian Delays Bicycle and pedestrian access across the Caltrain tracks and Alma Street were analyzed for all grade separation alternatives. Bike speed is assumed to be 10 miles per hour (mph), and pedestrian speed is assumed to be 3 feet per second. For alternatives where pedestrian/bicycle access is grade separated, the bike speed was assumed to be 8 mph to account for the change in Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 22  Packet Pg. 25 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 7 grade and the sharp turns to access the pedestrian/bicycle bridge. For alternatives where pedestrians and bicycles have to cross Alma Street at grade, the bicycle and pedestrian travel times include the wait time at the traffic signal on Alma. The following paths near the proposed grade separation were analyzed in coordination with the city. • Alma/Churchill o East/west bicycle and pedestrian travel times along Churchill Avenue between Mariposa Avenue and Emerson Street. • Alma/Meadow o East/west bicycle and pedestrian travel times along Meadow Drive between Wilkie Way and Ramona Street. o North/south bicycle and pedestrian travel times along Park Boulevard between Maclane Street and Davenport Way. • Alma/Charleston o East/west bicycle and pedestrian travel times along Charleston Road between Ruthelma Avenue and Carlson Court. o North/south bicycle and pedestrian travel times along Park Boulevard between Carolina Lane and Darlington Court. Alma/Churchill Avenue Intersection Table 4 provides a comparison of bicycle and pedestrian travel times between the Viaduct, Churchill Closure and Partial Underpass alternatives at the Alma/Churchill intersection. It is noted that the Viaduct alternative is not being considered for further evaluation so vehicular and cyclist/pedestrian delays under this alternative are provided only for comparison purposes. Under the Viaduct alternative, an elevated structure would carry the railroad tracks over Churchill Avenue, and the Alma/Churchill Avenue intersection would continue to provide a direct connection to all turning movements for pedestrians and bicycles. Pedestrians and cyclists would travel through the Alma/Churchill intersection, through which approximately 28,000 vehicles travel daily. Under the Churchill Closure alternative, Churchill Avenue would be closed off to the west of the Caltrain tracks, and Churchill Avenue would no longer provide an east-west connection for vehicles across Alma Street. However, pedestrian and bicycle access across Churchill Avenue would be maintained. Two options are being considered under this alternative, which differ in design with respect to pedestrian/bicycle access across Alma Street (see Figures 1 and 2). Under Alternative 1, pedestrians and bicycles would cross under the Caltrain tracks but would still need to cross Churchill Avenue at grade at the signal. Under Alternative 2, pedestrian/bicycle access across Alma Street would be provided via an underground tunnel that begins on the west side of the Caltrain tracks where Churchill Avenue is closed, then goes under the tracks and Alma Street and rises to the street level approximately 220 feet east of Alma Street. Under this alternative, pedestrians and bicyclists would not need to cross Alma Street at grade. Under the Partial Underpass alternative, access to Alma Street would be maintained by keeping Churchill Avenue partially open via a modified underpass. Pedestrian and bicycle access across Alma Street would be provided via a tunnel that traverses under the Caltrain tracks and Alma Street at Kellog Avenue (see Figure 3). As shown in Table 4, pedestrian and bicycle access under Churchill Closure (Option 1) and the Partial Underpass would have longer delays compared to the viaduct alternative as pedestrians and bicyclists would have to travel farther north and make multiple sharp turns to access the tunnel under the railroad tracks. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 23  Packet Pg. 26 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 8 Table 4 Bicycle and Pedestrian Delays at Alma/Churchill Road Daily # of Bicycles 1 Cyclists/Pedestrian navigate through a major signal? Yes (28,500 daily Vehicles) Yes (28,500 daily Vehicles)No No Notes 4 Pedestrian speed is assumed to be 3 feet/second. 6 See Figure 3 7 See Figure 4 8 See Figure 5 indicates reduced delays compared to the Hybrid/Trench/Viaduct alternatives. indicates increased delays compared to the Hybrid/Trench/Viaduct alternatives. 1800 0 4 0 2 Partial Underpass (Ped/Bike Tunnel) 8 Churchill Closure (Option 2) 7 # of Turns along the East/West Travel Path East/west Pedestrian - Travel Time (seconds) 3,4 (between Mariposa Avenue and Emerson Street) East/west Bicycle - Travel Time (seconds) 2,3 (between Mariposa Avenue and Emerson Street) Bike Route 1 Based on traffic counts conducted on 4/11/2023 and 4/12/2023 2 Bike speed is assumed to be 10 mph for the Viaduct alternative. Bike speed is assumed to be 8 mph for the Churchill Closure (Option 1) alternative and the Partial Underpass alternative to account for the change in grade and sharp turns along the travel path. 3 Under the Viaduct alternative and the Churchill Closure (Option 1) alternative, the bike/ped travel time accounts for the wait time at the Alma/Churchill traffic signal. With the Churchill Closure (Option 2) alternative and the Underpass alternative, pedestrians and cyclists traveling east/west will be completely separated from train and vehicular traffic on Alma Street. 5 Distance is measured from the midpoint at each intersection. Viaduct Churchill Closure (Option 1) 6 Alma Street/ Churchill Avenue Grade-Separation Alternatives Distance along Travel Path (feet) 5 143 212 53 157 383 587 263 600 790 1400 790 Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 24  Packet Pg. 27 of 57  Palo Alto Grade SeparaƟon Figure 1 Churchill Closure (Option 1) Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 25  Packet Pg. 28 of 57  Palo Alto Grade SeparaƟon Figure 2 Churchill Closure (Option 2) Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 26  Packet Pg. 29 of 57  Palo Alto Grade SeparaƟon Figure 3 Churchill Partial Underpass Alternative Figure 3 Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 27  Packet Pg. 30 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 1 2 Alma/Meadow Intersection Table 5 provides a comparison of bicycle and pedestrian travel times between the Hybrid/Trench and Underpass alternatives at the Alma/Meadow intersection. Under the Hybrid/Trench alternative, an elevated structure (viaduct) would carry the railroad tracks over Meadow Drive, and the Alma/Meadow intersection would continue to provide a direct connection to all turning movements for pedestrians and bicycles. Under the Underpass alternative, Meadow Drive would be lowered beneath Alma Street and the railroad tracks, and pedestrians and bicyclists traveling east/west would be completely separated from train and vehicular traffic (see Figure 4). Under this alternative, a two-way pedestrian/bicycle path would be located along the south side of Meadow Drive. Bicyclists and pedestrians traveling on westbound Meadow Drive would cross Meadow Drive via the marked crosswalks at Emerson Street and then cross Meadow Drive again near 2nd Street to get back onto the north side of the road. On northbound Park Boulevard, bicyclists would use the pedestrian/bicycle bridge to the west of Alma Street to cross Meadow Drive. Bicyclists on southbound Park Boulevard would use the crossing at 2nd Street to cross Meadow Drive. An additional delay time of 30 seconds was assumed at each of the crossings. As shown in Table 5, the Underpass would reduce delays for bicyclists and pedestrians traveling along Meadow Drive compared to the Hybrid/Trench. Along Park Boulevard, this alternative shows increased delays for bicyclists due to the additional turning movements required to cross over or around the underpass. Along Alma Street, this alternative shows reduced delays for pedestrians due to the removal of the traffic signal. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 28  Packet Pg. 31 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 1 3 Table 5 Bicycle and Pedestrian Delays at Alma/Meadow Daily # of Bicycles 1 Cyclists/Pedestrian navigate through a major signal? Yes (28,000 daily Vehicles) No EB 8 1600 1600 WB 9 1600 1680 EB 8 0 0 WB 9 0 4 NB 11 1000 1235 SB 10 1000 1412 NB 11 0 4 SB 10 0 4 NB 12 1595 1595 SB 12 1595 1595 NB 12 0 0 SB 12 0 0 Notes 1 Based on traffic counts conducted on 4/11/2023 and 4/12/2023 # of Turns along the North/south Travel Path along Park Boulevard East/west Pedestrian - Travel Time (seconds) 3,4 (between Wilkie Way and Romana Street) EB 8 650 530 WB 9 650 570 97 107 Distance along Travel Path (feet) 5 # of Turns along the East/West Travel Path Distance along Travel Path (feet) SB 10 97 153 224 224 North/south Pedestrian - Travel Time (seconds) (Alma St between Lindero Dr and Alma Village Cir) 7 598 650 532 570 EB 8 WB 9 NB 12 SB 12 North/south Bicycle - Travel Time (seconds) (Park Boulevard between Maclane Street and Davenport Way) 6 NB 11 138 209 East/west Bicycle - Travel Time (seconds) 2,3 (between Wilkie Way and Romana Street) Alma Street/ Meadow Road Grade-Separation Alternatives Bike Route Direction Hybrid/ Trench/ Viaduct Underpass 622 2 Bike speed is assumed to be 10 mph for the Hybrid/Trench alternatives. Bike speed is assumed to be 8 mph for the underpass alternative to account for the change in grade along the underpass and sharp turns to access the pedestrian/bike bridge to connect to the two-way cycle track. 3 Under the Hybrid/Trench alternatives, the bike/ped travel time accounts for the wait time at the Alma/Meadow traffic signal. With the underpass alternative, pedestrians and cyclists traveling east/west will be completely separated from train and vehicular traffic on Alma Street. Full pedestrians and cyclist movement maintained. Pedestrians and cyclists will have more circuitous routes traveling east/west across the corridor because the pedestrian/bike path is located on the south side of Meadow Drive. It is assumed that cyclists/pedestrians traveling on westbound Meadow Drive would cross Meadow Drive via the marked crosswalks at Emerson Street and then cross Meadow Drive again near 2nd Street to get back onto the right/north side of the road. An additional delay time of 30 seconds was assumed at each of the crossings. Distance along Travel Path (feet) # of Turns along the Travel Path on Alma Street Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 29  Packet Pg. 32 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 1 4 Table 5 (continued) Bicycle and Pedestrian Delays at Alma/Meadow 4 Pedestrian speed is assumed to be 3 feet/second. 8 See Figure 4 Path A 9 See Figure 4 Path B 10 See Figure 4 Path C 11 See Figure 4 Path D 12 See Figure 4 Path E indicates reduced delays compared to the Hybrid/Trench/Viaduct alternatives. indicates increased delays compared to the Hybrid/Trench/Viaduct alternatives. 7 For the underpass alternative, pedestrians on Alma Street would use the ped/bike bridge on the east side of Alma Street to cross Meadow Drive. 5 Distance is measured from the midpoint at each intersection. 6 With the underpass alternative, it is assumed that cyclists on northbound Park Boulevard would use the ped/bike bridge to the west of Alma to cross Meadow Drive and bicycles on southbound Park Boulevard would use the crossing at 2nd Street to cross Meadow Drive. A 30s delay was included for the crossing at 2nd Street. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 30  Packet Pg. 33 of 57  Palo Alto Grade SeparaƟon Figure 4 Cyclist/Pedestrian Travel Paths Near Alma/Meadow LEGEND = Northbound Travel Path Along Park Boulevard = Northbound/Southbound Travel Path Along Alma St = Eastbound Travel Path Along Meadow Drive = Westbound Travel Path Along Meadow Drive = Southbound Travel Path Along Park Boulevard EE E A A A B B B D D D C C C Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 31  Packet Pg. 34 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 1 6 Alma/Charleston Intersection Table 6 provides a comparison of bicycle and pedestrian travel times between the Hybrid/Trench alternatives and Underpass alternative at the Alma/Charleston intersection. Under the Hybrid/Trench alternative, an elevated structure (viaduct) would carry the railroad tracks over Charleston Drive, and the Alma/Charleston intersection would continue to provide a direct connection to all turning movements for pedestrians and bicycles. Under the Underpass alternative, Charleston Road would be lowered beneath Alma Street and the railroad tracks, and pedestrians and bicyclists traveling east/west would be completely separated from train and vehicular traffic (see Figure 2). Under this alternative, a two-way pedestrian/bicycle path would be located along the north side of Charleston Road. Bicyclists and pedestrians traveling on eastbound Charleston Road would use the pedestrian/bicycle bridge to the west of Alma Street to access the two-way cycle track and then cross Charleston Road via the marked crosswalks at Mumford Place to get back onto the south side of the road. On northbound Park Boulevard, bicyclists would use the pedestrian/bicycle bridge to the west of Alma Street to cross Charleston Road. Bicyclists on southbound Park Boulevard would use the crossing at Ruthelma Avenue to cross Charleston Road. An additional delay time of 30 seconds was assumed at each of the crossings. As shown in Table 6, the Underpass would reduce delays for bicyclists and pedestrians traveling along Charleston Road compared to the Hybrid/Trench. Along Park Boulevard, this alternative shows increased delays for bicyclists due to the additional turning movements required to cross over or around the underpass. Along Alma Street, this alternative shows slightly reduced delays for pedestrians due to elimination of some vehicular turning movements at the Alma/Charleston ramp signals. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 32  Packet Pg. 35 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 1 7 Table 6 Bicycle and Pedestrian Delays at Alma/Charleston Road Daily # of Bicycles 1 Cyclists/Pedestrian navigate through a major signal? Yes (33,000 daily Vehicles) No EB 8 2120 2370 WB 9 2120 2120 EB 8 0 5 WB 9 0 0 NB 11 540 875 SB 10 540 1255 NB 11 0 4 SB 10 0 4 NB 12 1605 1605 SB 12 1605 1605 NB 12 0 0 SB 12 0 0 Notes 1 Based on traffic counts conducted on 4/11/2023 and 4/12/2023 Alma Street/ Charleston Road Grade-Separation Alternatives Bike Route Direction Hybrid/ Trench/ Viaduct Underpass WB 9 253 209 429 East/west Bicycle - Travel Time (seconds) 2,3 (between Ruthelma Avenue Carlson Court) EB 8 253 236 East/west Pedestrian - Travel Time (seconds) 3,4 (between Ruthelma Avenue Carlson Court) EB 8 819 790 WB 9 819 707 Distance along Travel Path (feet) Distance along Travel Path (feet) 5 # of Turns along the East/West Travel Path North/south Bicycle - Travel Time (seconds) (Park Blvd between Carolina Ln and Darlington Ct) 6 NB 11 SB 10 66 139 66 76 # of Turns along the North/south Travel Path along Park Boulevard North/south Pedestrian - Travel Time (seconds) (Alma St between Ely Pl and Lindero Dr) 7 NB 12 647 620 SB 12 647 620 Distance along Travel Path (feet) # of Turns along the Travel Path on Alma Street 2 Bike speed is assumed to be 10 mph for the Hybrid/Trench/Viaduct alternatives. Bike speed is assumed to be 8 mph for the underpass alternative to account for the change in grade along the underpass and sharp turns to access the pedestrian/bike bridge to connect to the two-way cycle track. 3 Under the Hybrid/Trench alternatives, the bike/ped travel time accounts for the wait time at the Alma/Charleston traffic signal. With the underpass alternative, pedestrians and cyclists traveling east/west will be completely separated from train and vehicular traffic on Alma Street. Full pedestrians and cyclist movement maintained. Pedestrians and cyclists will have more circuitous routes traveling east/west across the corridor because the pedestrian/bike path is located on the north side of Charleston Road. With the underpass alternative, it is assumed that eastbound bicycles on Charleston Road would access the two-way cycle track via the bike/ped bridge to the west of Alma to connect to the two-way cycle track on the northside of Charleston Road and then would use the crossing at Mumford Place to access the eastbound bike lane on Charleston Avenue. An additional delay times of 30 seconds was assumed at the Mumford Place crossing. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 33  Packet Pg. 36 of 57  Palo Alto Grade Separation January 16, 2024 P a g e | 1 8 Table 6 (continued) Bicycle and Pedestrian Delays at Alma/Charleston 4 Pedestrian speed is assumed to be 3 feet/second. 8 See Figure 5 Path A 9 See Figure 5 Path B 10 See Figure 5 Path C 11 See Figure 5 Path D 12 See Figure 5 Path E indicates reduced delays compared to the Hybrid/Trench/Viaduct alternatives. indicates increased delays compared to the Hybrid/Trench/Viaduct alternatives. 7 For the underpass alternative, pedestrians on Alma Street would use the signal at Alma/Charleston Road Ramps to cross Charleston Road. 5 Distance is measured from the midpoint at each intersection. 6 With the underpass alternative, it is assumed that cyclists on northbound Park Boulevard would use the ped/bike bridge to the west of Alma to cross Charleston Road and bicycles on southbound Park Boulevard would use the crossing at Ruthelma Avenue to cross Charleston Road. A 30s delay was included for the crossing at Ruthelma Avenue. Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 34  Packet Pg. 37 of 57  E E A A B B D D C C LEGEND = Northbound Travel Path Along Park Boulevard = Northbound/Southbound Travel Path Along Alma St = Eastbound Travel Path Along Charleston Rd = Westbound Travel Path Along Charleston Rd = Southbound Travel Path Along Park Boulevard E A B D C Palo Alto Grade SeparaƟon Figure 5 Cyclist/Pedestrian Travel Paths Near Alma/Charleston Item 1 Attachment B: Hexagon Memorandum on Intersection, Bicycle, and Pedestrian Delay Analysis for the Palo Alto Grade Separation Project        Item 1: Staff Report Pg. 35  Packet Pg. 38 of 57  1/3 To: Ripon Bhatia, City of Palo Alto CC: Peter DeStefano Lynn McIntyre AECOM 300 Lakeside Drive Suite 400 Oakland CA 94612 aecom.com Project name: Palo Alto Grade Separation Study Project ref: From: Nikita Subramanian Date: January 29, 2024 Sea Level Rise Memo Executive Summary AECOM was tasked to evaluate the effects of sea level rise on the remaining railroad grade separation alternatives in the City of Palo Alto. Two parameters were considered for the sea level rise evaluation: projected sea level rise for the years 2050 and 2100 from the City of Palo Alto Sea Level Rise Vulnerability Assessment, and increased groundwater elevations resulting from sea level rise.  The Meadow-Charleston Trench alternative would be at some risk for the year 2100 sea level rise inundation. The remaining alternatives would not be exposed to sea level rise inundation.  The Meadow-Charleston Trench and the Meadow-Charleston Underpass would have project components within existing groundwater elevations. Increased groundwater elevation from sea level rise increases the potential for impacts to these alternatives from emergent groundwater.  While project components for the Meadow-Charleston Hybrid would not be within existing groundwater levels, the lowest proposed underpass elevation is close to current groundwater levels. Increased groundwater elevations from sea level rise might expose the underpass to emergent groundwater by 2100. Increased groundwater elevations from sea level rise can result in cracks, potholes, and sinkholes in the road.  The Churchill Closure with Mitigations, the Churchill Partial Underpass, and the Meadow-Charleston Viaduct are not anticipated to be affected by sea level rise or emergent groundwater. Item 1 Attachment C: Sea Level Rise Assessment        Item 1: Staff Report Pg. 36  Packet Pg. 39 of 57  Memo AECOM 2/3 Sea Level Rise Evaluation Over the past century, the sea level in the San Francisco Bay Region has increased by 8 inches (https://oehha.ca.gov/climate- change/epic-2022/impacts-physical-systems/sea-level-rise). The majority of the alternatives would not be affected by sea-level rise (SLR) for the years 2050 and 2100, based on projections from the City of Palo Alto Sea Level Rise Vulnerability Assessment (Assessment). Furthermore, the existing Caltrain routes and stations in the City would not be exposed to inundation or 100-year storm-tide flooding at a given amount of SLR, except for less than 1 mile of Caltrain routes in the event of an 84-inch SLR scenario, per the Assessment. The Meadow-Charleston Trench Alternative shows a profile elevation of 4 feet as the lowest proposed track elevation profile. SLR for the year 2100 is projected to be approximately 3.42 feet. In addition, this profile is shown to be constructed well into the groundwater table, which will require the use of a pump station for dewatering. The pump would be installed at an elevation just below the proposed track elevation, which would be affected by SLR projections for the year 2100. No other alternatives would be affected by SLR. As sea levels rise, the surface of the shallow groundwater table, especially in low-lying coastal communities, will also rise. Much of the area of the City of Palo Alto is low-lying. Emergent groundwater occurs when the water table rises to or above the ground surface and creates ponding. Groundwater within 6 feet of the surface can damage roadways when it meets the bottom of the roadbed underground. Over time, the roadbed could deteriorate from below, increasing the likelihood of cracks, potholes, and sinkholes. Per the Assessment, the future groundwater conditions were projected taking a 1:1 correlation between SLR and shallow groundwater rise, as a conservative approximation. This means that probable increases in SLR listed in the Table 1 are assumed to be the same increases for groundwater levels as well. Less than 1 mile of existing Caltrain routes would be exposed to emergent groundwater for all scenarios of SLR (12, 24, 36, 48, 66, and 84 inches). Since the Meadow-Charleston Trench and Meadow-Charleston Underpass profiles would be constructed well into the groundwater table, emergent groundwater could be a potentially significant effect, combined with SLR. Groundwater depletion and further studies will need to be prepared to further assess the feasibility of this Alternative. The Meadow-Charleston Hybrid Alternative is at some risk for emergent groundwater. The Churchill partial underpass Alternative, Churchill closure Alternative, and Meadow-Charleston Viaduct Alternative would not be substantially impacted by emergent groundwater projections. Item 1 Attachment C: Sea Level Rise Assessment        Item 1: Staff Report Pg. 37  Packet Pg. 40 of 57  Memo AECOM 3/3 Table 1 - Elevation Summary Alternative Lowest Proposed Track Elevation (ft) Lowest Road or Ped/Bike Underpass Elevation (ft) Approx. Groundwater Elevation range (ft) Sea-level risea 2050 (66% probability) (ft) Sea-level risea 2100 (66% probability) (ft) SLR Impact Ratingb Emergent Groundwater Impact Ratingb Churchill Closure 47 27 at Kellogg, 20 at Seale 8-11 1.08 3.42 No impact No Impact Churchill Partial Underpass 47 25 8-11 1.08 3.42 No Impact No Impact Meadow- Charleston Hybrid 35 30 at Meadow 21 1.08 3.42 No Impact Potential Impact to roadway 34 at Charleston 22 Meadow- Charleston Trench 4 33 at Meadow 21-22 1.08 3.42 Some Impact Most Impact Meadow- Charleston Underpass 36 12 at Meadow 21 1.08 3.42 No Impact Most Impact 16 at Charleston 22 Meadow- Charleston Viaduct 35 33 at Meadow 21-22 1.08 3.42 No Impact No Impact Projections represent an SLR increase above the baseline year of 2000. Sources: a. City of Palo Alto. 2022. Sea Level Rise Vulnerability Assessment, Available: https://www.cityofpaloalto.org/files/assets/public/v/1/public-works/environmental-compliance/sea-level-rise/palo-alto-sea- level-rise-vulnerability-assessment-june-2022-062822-linked-final.pdf. Current Global Sea Level = 3.97 in (101mm), NASA Global Climate Change. Available: https://climate.nasa.gov/vital-signs/sea-level/ b. Per City of Palo Alto Summary of Evaluation/City Council-Adopted Criteria Item 1 Attachment C: Sea Level Rise Assessment        Item 1: Staff Report Pg. 38  Packet Pg. 41 of 57  Connecting Palo Alto Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 39  Packet Pg. 42 of 57  Connecting Palo Alto Prepared for: City of Palo Alto Prepared by: AECOM 150 California Street, Suite 200 San Francisco, CA 94111, USA aecom.com Copyright © 2024 by AECOM All rights reserved. No part of this copyrighted work may be reproduced, distributed, or transmitted in any form or by any means without the prior written permission of AECOM. PreparedFor: City of Palo Alto AECOM Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 40  Packet Pg. 43 of 57  Connecting Palo Alto Table of Contents 1.Comparative Analysis........................................................................................... 1 1.1 Introduction......................................................................................................................................................1 Heat Island Effect.............................................................................................................................................1 Introduction......................................................................................................................................................1 Methodology ....................................................................................................................................................1 Evaluation Approach........................................................................................................................................2 Findings ...........................................................................................................................................................3 Stormwater Management.................................................................................................................................6 Introduction......................................................................................................................................................6 Methodology ....................................................................................................................................................6 Findings ...........................................................................................................................................................6 References ........................................................................................................... 1 1.2 1.2.1 1.2.2 1.2.3 1.2.4 1.3 1.3.1 1.3.2 1.3.3 2. Figures Figure 1. Diagram Illustrating Longer Northward Shadows due to Solar Orientation .....................................................2 Tables Table 1. Albedo Values..................................................................................................................................................1 Table 2. Pavement and Vegetated Areas by Alternative................................................................................................2 Table 3. Comparison of Shaded Areas from Trees between Alternatives......................................................................3 Table 4. Runoff Coefficient Values.................................................................................................................................6 Table 5. Churchill Ave Heat Island Effect Summary ......................................................................................................1 Table 6. Meadow-Charleston Heat Island Effect Summary...........................................................................................2 Table 7. Churchill Ave Stormwater Summary ................................................................................................................3 Table 8. Meadow-Charleston Stormwater Summary.....................................................................................................4 PreparedFor: City of Palo Alto AECOM Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 41  Packet Pg. 44 of 57  Connecting Palo Alto 1. Comparative Analysis 1.1 Introduction This study is a preliminary comparative analysis between three alternatives for Churchill Avenue and four alternatives for Meadow-Charleston for construction and their impacts on heat island effects and stormwater management. In evaluating the heat island effects, consideration was given to the albedo of pavement areas and shaded areas cast by trees in vegetated areas. This study is accompanied with exhibits graphically summarizing the areas estimated for the alternatives. 1.2 Heat Island Effect 1.2.1 Introduction Albedo plays a pivotal role in the heat absorption and retention of pavements, influencing local microclimates and heat island effects. Albedo is a measure of the ability of an object to reflect solar radiation, where values range between 0 (no sunlight reflected) to 1 (all sunlight is reflected). Generally, lighter colored materials reflect more sunlight and have higher albedo values than darker colored materials. For the purpose of this comparative analysis, assumptions and generalizations were made for pavement types and albedo values, as shown in Table 1. Table 1. Albedo Values Approximate Albedo Approximate Weathered AlbedoSurface Type (assumed average)(assumed average) New Roadway Pavement (Asphalt)0.05 – 0.10 (0.08)0.10 – 0.15 (0.13) 0.25 ‐ 0.30 (0.28) 0.15 – 0.18 (0.17) New Pedestrian and Bicycle Pathway Pavement (Gray Concrete)0.35 – 0.40 (0.38) New Sidewalk (Gray Concrete) New Sidewalk (White Concrete) Vegetated Area (Deciduous Trees) 0.35 ‐ 0.40 (0.38) 0.70 – 0.80 (0.75) 0.15 – 0.18 (0.17) 1.2.2 Methodology Pavement areas considered in this analysis include roadway pavement, sidewalk, and pedestrian pathway pavement, and railroad undercrossing pavement. Albedo values1,2 are provided in ranges, where concrete pavement albedo values are generally higher (more sunlight reflected) when newly constructed and typically decreases with aging, and asphalt pavement albedo values are generally lower (more sunlight absorbed) when newly constructed and typically increases with aging. Pavement area estimates are summarized in Table 2. Roadway and sidewalk/bicycle pathway pavement surfaces were assumed to be completely comprised of asphalt and concrete, respectively. Note that the albedo of vegetated areas may also be considered, and the albedo values of trees are often higher than asphalt surfaces. PreparedFor: City of Palo Alto AECOM 1 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 42  Packet Pg. 45 of 57  Connecting Palo Alto Table 2. Pavement and Vegetated Areas by Alternative Total Roadway Pavement Area Total Vegetated Area Total Pedestrian and Bicycle Pathway Pavement Area Property Acquisition Total Vegetated Area Location Alternative Underpass (sf)(sf)(sf)(sf)(sf) 101,840 24,520 33,390 24,520 Closure with Mitigations (Option 1) Closure with Mitigations (Option 2) 7,062 9,390 16,676 17,266 9,390 Churchill Ave 10,992 11,820 11,820 Viaduct Trench Hybrid 129,602 159233 8,130 3370 22,193 118740 20503 46781 8,130 3370 Meadow‐Charleston Viaduct Underpass 1.2.3 Evaluation Approach The proposed improvements for the viaduct and trench alternatives are limited to the extents of the existing railroad tracks and determined to have negligible impacts on heat island effects. As a result, the viaduct and trench alternatives both Churchill Avenue and Meadow-Charleston were determined to have negligible/neutral impacts to heat island effects and not included in the evaluation. The Churchill Avenue Underpass alternative was estimated to have a significantly larger construction area than both options of the Closure with Mitigations alternative, due to roadway grading requirements to accommodate a vehicular underpass for Churchill Avenue. Although the Underpass alternative is estimated to have a greater relative negative heat island effect due to a total pavement area of on the order of 5 to 7 times greater than the Closure with Mitigations alternative, the larger construction area of the Underpass alternative does provide additional opportunities for new vegetated areas that can provide shading from new trees and act to reduce total heat gain. If the impact of solar orientation and resultant projected shadows are considered, east-west oriented trees project longer shadows onto pavement north of the trees, as illustrated in Figure 13. Alma Street is generally northwest-southeast oriented, so the Underpass and Closure with Mitigations (Option 1) alternatives have the largest potential to take advantage of this benefit from the solar orientation due to the larger construction areas and placement of trees along Alma Street. Figure 1. Diagram Illustrating Longer Northward Shadows due to Solar Orientation Trees are planted on the order of every 40 feet along the length of a vegetated area and have a 30-foot diameter canopy. Shade from only one side of a tree was considered to provide shade onto adjacent pavement (i.e., the portion of a tree canopy furthest away from the pavement is assumed to not contribute to shading pavement areas). As shown on Table 2, while the Underpass alternative has the largest construction extents, it also has greater opportunities for new vegetated areas. As a result, the Underpass PreparedFor: City of Palo Alto AECOM 2 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 43  Packet Pg. 46 of 57  Connecting Palo Alto alternative was estimated to provide on the order of 2 to 5 times the shaded area as compared to both options of the Closure with Mitigations alternative. Table 3. Comparison of Shaded Areas from Trees between Alternatives Estimated Shading over Pavement from Tree Canopies2 Number of Trees1Length of Vegetated AreaLocationAlternative (sf)(ft) Underpass 2600 65 20 23000 7100Closure with Mitigations (Option 1)820 Churchill Ave Closure with Mitigations (Option 2)1707 40 14200 Viaduct Trench 360 840 9 21 9 3200 7,500 3,200 25500 Hybrid Meadow‐Charleston Viaduct Underpass 360 2880 72 Assumptions: 1 2 The estimated number of trees is determined by assuming a tree planted every 40 linear feet Projected tree canopy is determined by assuming mature tree canopies at a 30' diameter (15' projected from the trunk) Additional considerations in the area estimate include the property acquisitions for the Meadow-Charleston alternatives and improvements at the intersection of Alma St & Kingsley Avenue for the Churchill Closure with Mitigation alternative (both options). Note that the Meadow-Charleston property acquisitions assumed in the evaluation to be 75% concrete and 25% vegetated surface area in the proposed conditions. 1.2.4 Findings Table 5 is a summary of total pavement areas, vegetated areas, albedo values for these surface types, and an estimate of albedo ratings and total heat island effect, between the alternatives. Also included is an existing conditions/no project baseline alternative (with an “E” suffix). The albedo rating estimate shown for each surface type is the product of the total surface area of the surface type and albedo value. Also, the total shaded area from tree canopies was considered as a credit (i.e., the shaded area is assumed to not contribute to the heat island effect). A higher Albedo Rating and Total Heat Island Effect Ratio indicates a lower heat island effect as a result of reflecting more sunlight. Therefore, the Total Heat Island Effect Rating was estimated as the sum of all albedo ratings for each surface type, with an additional positive credit applied from the total shaded area from tree canopies. The Total Heat Island Effect is a ratio of the sum of albedo ratings of the different surface types adjusted to account for shaded areas on pavement areas and sum of all surface types. For the alternatives at Churchill Avenue, there is a clear distinction in the size of construction extents between the two alternatives. Pavement and vegetated area work is significantly higher in the Underpass alternative due to roadwork grading to accommodate a new vehicular underpass, resulting in larger estimates of new and replaced pavement and new vegetated areas. The impacts on heat island effects for each alternative may be summarized as: Underpass alternative: This alternative was estimated to have the largest overall new construction and replacement of pavement and vegetated areas, by approximately an order of 4 to 5 times larger than the next largest alternative (Closure with Mitigations). Due to the larger construction extents, this alternative provides the most potential for shading from trees onto the pavement at an estimated 23,000 sf. However, this alternative has the lowest Total Heat Island Effect Ratio, suggesting a lower PreparedFor: City of Palo Alto AECOM 3 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 44  Packet Pg. 47 of 57  Connecting Palo Alto and similar benefit to reducing the heat island effect per unit of impacted surface area than the Closure with Mitigations, Option 1 and Closure with Mitigations, Option 2, respectively. Closure with Mitigations alternative: Although similar, both options for this alternative may be considered to have unique advantages: ─Option 1 – This option may take more advantage of solar orientation by having more trees aligned east-west, providing longer shadows from trees along Alma Street onto adjacent roadway. ─Option 2 – This option provides more opportunity to plant trees in a north of Alma Street, along Churchill Avenue, while having less trees aligned east-west and benefitting to a smaller degree from solar orientations. Viaduct alternative: With improvements limited to the existing railroad tracks, this alternative is estimated to have negligible impacts on heat island effects when compared to its existing conditions. The alternatives at Meadow-Charleston follow a similar trend, with a clear distinction in size of construction extents between the Underpass and Hybrid alternatives but with a difference in shading opportunities. The alternatives for this location are summarized in Table 6. Underpass alternative: This alternative was estimated to have construction extents on the order of 2 times larger than the next largest alternative (Hybrid). This Underpass alternative was also found to decrease shading canopies due to the conversion of existing vegetated areas to paved surfaces. Although having a larger construction extent and a decrease in shading, this alternative was estimated to have an approximate 20% improvement toward heat island effects when compared to its existing conditions, largely due to the construction and replacement of concrete surfaces that typically have higher albedos when newly constructed.   Hybrid alternative: This alternative was estimated to have an impact on heat island effects, largely due to the replacement of existing asphalt surfaces for roadway grading and an understanding that newly constructed asphalt pavement is typically lower in albedo. Trench and Viaduct alternatives: Similar to that of the Churchill Viaduct alternative, these improvements at Meadow-Charleston are limited to the existing railroad tracks. Due to the minimal improvements and changes to land use, these two alternatives are estimated to have negligible impacts on heat island effects when compared to its existing conditions. In general, the existing conditions/no project alternative with higher albedo values associated with weathered asphalt surface (lighter) generally have a lower heat island effect rating indicating older asphalt reflects more sunlight; whereas concrete typically darkens with age indicating new sidewalk areas with a higher albedo value reflect more sunlight than older/weathered concrete. With an understanding that surfaces with a darker albedo generally warms the surrounding climate4, locations with very dark pavement may be understood to feel much hotter than those with light-colored surfaces. In summary: 1. Churchill Ave alternatives: a.Underpass, Closure with Mitigations, and Viaduct Alternatives Comparison: Table 5 illustrates that the Underpass alternative performs worse than both options of the Closure with Mitigations alternative, observed through the estimated increase in Heat Island Effect (lower Heat Island Effect ratio indicating less reflecting of the sun on a per square foot basis), but noted to only perform slightly worse than Closure with Mitigations alternative, Option 2. Additionally, although significantly varying in construction extents, the Underpass alternative is estimated to have a similar minimal impact to heat island effects as the Viaduct alternative. b. c. Closure with Mitigations Option Comparison: Option 1 Heat Island Effect Ratio outperforms Option 2 by on the order of 40%; and, Overall performance: The Closure with Mitigations, Option 1 provides the overall best performance of the project alternatives for Churchill Avenue. PreparedFor: City of Palo Alto AECOM 4 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 45  Packet Pg. 48 of 57  Connecting Palo Alto 2.Meadow-Charleston Ave alternatives: a.Underpass, Hybrid, Viaduct, and Trench Alternatives Comparison: The Underpass alternative performs as the best alternative at Meadow-Charleston, as shown in Table 6, with an estimated improvement toward heat island effects when compared to existing conditions. The improvement is largely due to the construction and replacement of concrete pavements, increasing the overall albedo of the conditions in this alternative. On the contrary, the Hybrid alternative involves relatively significantly more asphalt pavement replacement, resulting in an overall lower albedo. Similar to Churchill Avenue, the Viaduct and Trench alternatives have minimal changes to land use and improvements due to being limited to the existing railroad tracks, so impacts to heat island effects are estimated to be negligible. b.Overall performance: The Underpass provides the overall best performance of the project alternatives for Meadow-Charleston. PreparedFor: City of Palo Alto AECOM 5 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 46  Packet Pg. 49 of 57  Connecting Palo Alto 1.3 Stormwater Management 1.3.1 Introduction Generally, stormwater management involves the planning and implementation of strategies to manage and mitigate the effects of runoff generated during precipitation events (e.g., flooding, erosion, and water pollution). Runoff coefficients are parameters often used to represent the portion of precipitation that is expected to result in surface runoff, where values range between 0 (complete infiltration) and 1 (all precipitation becomes direct runoff). The value of these coefficients is influenced by various factors, including land cover, land use, and soil type. For the purposes of this comparative analysis, assumptions and generalizations were made for runoff coefficient values, as shown in Table 4. Table 4. Runoff Coefficient Values Approximate Runoff Surface Type Coefficient Roadway Pavement (Asphalt)0.95 1.00Pedestrian and Bicycle Pathway Pavement (Concrete) Vegetated Area (Vegetated) Railroad Ballast (Ballast) 0.20 0.70 1.3.2 Methodology For each alternative, changes in overall runoff coefficients were estimated as a measure of relative increases or decreases in runoff generation, as compared to existing conditions. Changes in runoff coefficients in each alternative were estimated by calculating the approximate percent change in overall runoff coefficients between the existing and proposed conditions. Surface types in this analysis included asphalt roadway pavement, concrete pedestrian and bicycle pathway pavement, vegetated areas, and railroad ballast/gravel. Roadway and sidewalk/bicycle pathway pavement surfaces were assumed to be completely comprised of asphalt and concrete, respectively. 1.3.3 Findings Tables 7 and 8 summarizes the estimated areas and associated runoff coefficients for each surface type and the percent change in overall runoff coefficients between the existing and proposed conditions for each alternative. Similar to the Tables 5 and 6 for the heat island effect evaluation, the existing conditions/no project baseline alternatives are labeled with an “E” suffix. Column E is the overall runoff coefficient for each alternative, calculated as the weighted average of runoff coefficients of each surface type. Column G is the estimated percent change between existing and proposed conditions, for each alternative, in Column E. Churchill Avenue - For the alternatives at Churchill Avenue, the construction extents for the Underpass and Viaduct alternatives are distinctly larger than both options of the Closure with Mitigations alternative. Since the land areas affected for the Underpass and Viaduct alternatives are larger, the overall increase (Underpass alternative) and decrease (Viaduct alternative) in volume of runoff will also be larger. The impact on runoff generation for each alternative may be summarized as: PreparedFor: City of Palo Alto AECOM 6 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 47  Packet Pg. 50 of 57  Connecting Palo Alto Underpass alternative: This alternative was the only alternative estimated to have an increase (i.e., positive value in Column G of Table 7) in runoff volume generation, when compared to its existing baseline condition. This expected increase in runoff volume generation is understood to be largely due to the conversion of existing vegetation (with higher permeability) to pedestrian and bicycle pathways (with lower permeability). Closure with Mitigations alternative: The estimated percent change for both options of this alternative are similar, with both options estimated to have an expected decrease in runoff generation when compared to existing conditions. Differences between the options are mostly due to the extent of converting existing concrete and asphalt surfaces to vegetated areas. ─Option 1 – This option includes the conversion of the southwest roadway asphalt pavement near the intersection of Alma St and Churchill Ave to vegetated areas, resulting in an expected decrease in runoff volume generation from existing conditions. This option also includes new pedestrian and bicycle pathway pavement along Alma St to accommodate an underpass below the railroad tracks. ─Option 2 – Similar to Option 1, this option also includes the conversion of the southwest roadway at the intersection of Alma St and Churchill Ave to vegetated areas. The major difference in Option 2 and Option 1 is the configuration of the underpass for pedestrians and bicyclists. Instead, the underpass for Option 2 is designed to follow Churchill Ave and under the railroad tracks, not requiring the conversion of existing vegetated areas into new concrete and/or asphalt surfaces as shown in Option 1. Viaduct alternative: This alternative was estimated to have the largest construction extents due to the improvements following an estimated 4200-foot length of existing railroad tracks to accommodate the viaduct. With assumptions that the area under the raised viaduct will be 75% vegetated and all runoff generated on the viaduct will be captured in these vegetated areas, an overall reduction in runoff volume generation from existing conditions was estimated. Meadow-Charleston - The alternatives at Meadow-Charleston follow similar trends as Churchill Avenue, with the Underpass and Viaduct alternatives estimated to have an increase and decrease in runoff volume generation, respectively. The alternatives at this location also include the Hybrid and Trench alternatives, with a distinctly large amount of estimated increased runoff volume generation for the Trench alternative. The impact on runoff generation for each alternative may be summarized as: Trench alternative: This alternative was estimated to have the largest expected increase in runoff volume generation. Similar to the viaduct alternative, the trench alternative follows a relatively large length of the existing railroad tracks. However, the trench alternative involves lowering the existing railroad tracks and does not provide the same opportunity to capture runoff in vegetated areas below. As a result, the estimated increase in runoff generated from converting existing railroad ballast to concrete in the trench is understood to require stormwater management.    Hybrid alternative: The hybrid alternative was estimated to have a relatively minimal increase in runoff volume generation due to the proposed improvements largely involving the grading of existing roadways and having minimal changes to land use and surface types. Viaduct alternative: Following the same understanding and assumptions of the vegetated areas as the Churchill Ave Viaduct alternative, this alternative was estimated a decrease in runoff volume generation from existing conditions. Underpass alternative: This alternative was estimated to have the second largest increase in runoff volume generation when compared to existing conditions among Meadow-Charleston alternatives, greater than the next largest (i.e., Hybrid alternative) on the order of about 12 times. The Underpass alternative has the largest construction extents and involves the most improvements outside of the existing railroad tracks, among all alternatives for this location. The improvements include a relatively significant conversion of existing more permeable vegetated areas to less permeable roadway and pedestrian/bicycle pathway pavements. PreparedFor: City of Palo Alto AECOM 7 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 48  Packet Pg. 51 of 57  Connecting Palo Alto In summary: 1.Churchill Alternatives: a.Underpass, Closure with Mitigations, and Viaduct Alternatives Comparison: Table 7 shows that, for the estimated percent change in runoff volume generation from existing conditions, the Underpass alternative performs the worst (i.e., highest positive percent change) when compared to both options of the Closure with Mitigations alternative and Viaduct alternative, in Column G. b. c. Closure with Mitigations Option Comparison: The percent change in runoff volume generation from existing conditions for Option 2 was estimated to perform similarly to Option 1, outperforming Option 1 on the order of 70%. Closure with Mitigations and Viaduct Alternatives Comparison: All alternatives and options were estimated to have a reduction in runoff volume generation when compared to existing conditions. The percent change between these alternatives and options are relatively similar, with the Closure with Mitigation (Option 2) alternative estimated to perform the best on a percent change basis, but the Viaduct alternative performing marginally better than the Closure with Mitigations (Option 1) alternative. However, a clear distinction between the two alternatives is the extent of improvements being on the order of 5 times larger and along the existing railroad tracks for the Viaduct alternative, as opposed to the smaller construction extents involving significantly more roadway improvements at the intersection of Churchill Ave for the Closure with Mitigations alternative. As a result, the Viaduct alternative is expected to have the larger overall decrease in volume of runoff from existing conditions. d.Overall performance: The Viaduct alternative was estimated to provide the best overall stormwater performance of the project alternatives for Churchill Avenue. 2.Meadow-Charleston Alternatives: a.Underpass, Hybrid, Viaduct, and Trench Alternatives Comparison: Table 8 shows that, for the estimated percent change in runoff volume generation from existing conditions, the Trench alternative performs the worst among the alternatives at Meadow-Charleston. The expected increase in runoff volume generation is understood to be due to increased surface imperviousness from the conversion of existing railroad ballast to concrete along the new trench. The Underpass alternative was estimated to have the next largest increase in runoff volume generation, and this estimated increased is largely due to the conversion of existing vegetated areas into pedestrian/bicycle pathways. The Hybrid alternative was estimated to have the least amount of increased runoff volume generation, since this alternative has minimal changes to land use and surface types. Lastly, the only alternative to have an estimated reduction in runoff volume generation from existing conditions, was the Viaduct alternative. An important consideration for the results of the Viaduct alternative is that the estimated percent change in runoff volume generation is largely influenced by the assumptions that the new vegetated areas under the viaduct will completely capture the runoff generated from the concrete viaduct. b.Overall performance: The Viaduct alternative was estimated to provide the best overall stormwater performance of the project alternatives for Meadow-Charleston. PreparedFor: City of Palo Alto AECOM 8 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 49  Packet Pg. 52 of 57  Connecting Palo Alto Table 5. Churchill Avenue Heat Island Effect Summary [M=(J+K+L) /[A][B][C]New Pavement [G][H][I][J][K][L][N][O] (A+B+C)] Total Roadway Pavement Area Total Vegetated Area Total Pedestrian and Bicycle Pathway Pavement Area [D=A+C] Total New [E=A/D] % Roadway [F=C/D] % Pedestrian and Total Shaded Area from Tree Canopies onto ADJUSTED Total Roadway Pavement Area ADJUSTED Total Pedestrian and Roadway Pavement Albedo Vegetated Area New Pedestrian and Bicycle Pathway Pavement =I*0.38 Total Heat Island Effect Total Construction Extents % Change from Existing Total Heat Island Effect RatingPavement=H*0.08 Rating =A+B+C Bicycle Bicycle =A‐(E*G)Pathway Pavement Area ((‐) = reduction (+) = increase)Alternative Pavement =C‐(F*G) Credit (sf) Albedo Rating Albedo Rating Albedo Rating (Deciduous Trees = 0.17) (Gray Concrete = 0.38)(sf)(sf)(sf)(sf)(sf)(sf)(Asphalt = 0.08)(sf) Underpass 101,840 7,062 24,520 9,390 33,390 16,676 135,230 23,738 75.3% 29.7% 24.7% 70.3% 23,000 7,100 84,519 4,950 27,711 11,688 6,762 396 4168 1596 10,530 4,442 0.134 0.194 159,750 28,440 ‐2.8% Closure with Mitigations (Option 1)22.5% Closure with Mitigations (Option 2)10,992 11,820 17,266 28,258 38.9%61.1%14,200 5,468 8,590 437 2009 3,264 0.142 35,390 17.4% Viaduct (Deciduous Trees = 0.17) (Gray Concrete = 0.28)(Asphalt = 0.13) 10,941Underpass (E)102,764 15,824 32,690 6,637 24,296 10,239 127,060 26,063 80.9% 60.7% 19.1% 39.3% 23,000 4,600 84,162 13,031 19,898 8,432 5557 1128 5,571 2,361 0.138 0.159Closure with Mitigations (Option 1) (E)1,694 Closure with Mitigations (Option 2) (E)24,362 4,351 8,808 33,170 73.4%26.6%10,700 16,503 5,967 2,145 740 1,671 0.121 Viaduct (E) PreparedFor: City of Palo Alto AECOM 1 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 50  Packet Pg. 53 of 57  Connecting Palo Alto Table 6. Meadow-Charleston Heat Island Effect Summary [M=(J+K+L) /[A][B][C]New Pavement [G][H][I][J][K][L][N][O] (A+B+C)] Converted Property Acquisition (75% Ped/Bike Pavement 25% Vegetated Area) Total Roadway Pavement Area Total Vegetated Area Total Pedestrian and Bicycle Pathway Pavement Area [D=A+C] Total New [E=A/D] % Roadway [F=C/D] % Pedestrian and Total Shaded Area from Tree Canopies onto ADJUSTED Total Roadway Pavement Area ADJUSTED Total Pedestrian and Bicycle Pathway Pavement Area Roadway Pavement Albedo Vegetated Area New Pedestrian and Bicycle Pathway Pavement Total Heat Island Effect Total Construction Extents % Change from Existing Total Heat Island EffectPavement=H*0.08 Rating =A+B+C Bicycle Pavement =A‐(E*G)Alternative =I*0.38 ((‐) = reduction (+) = increase) =C‐(F*G) Credit (sf) Albedo Rating Albedo Rating Albedo Rating (Deciduous Trees = 0.17) (Gray Concrete = 0.38)(sf)(sf)(sf)(sf)(sf)(sf)(Asphalt = 0.08)(sf) Trench Hybrid 20,503 46,781 129,602 159,233 8,130 3,370 22,193 151,795 277,973 85.4% 57.3% 14.6% 42.7% 3,200 7,500 126,870 154,937 21,725 10,150 1382 573 8,256 0.124 0.202 159,925 281,343 ‐17.8% Viaduct Underpass 118,740 115,536 12,395 43,904 19.7% (Deciduous Trees = 0.17) (Gray Concrete = 0.28)(Asphalt = 0.13) Trench (E) Hybrid (E)20,503 46,781 124,588 116,450 8,130 22,193 84,153 146,781 200,603 84.9% 58.1% 15.1% 41.9% 3,200 121,872 101,647 21,709 73,456 15,843 13,214 1382 6,079 0.150 0.169 Viaduct (E) Underpass (E)75,384 25,500 12815 20,568 PreparedFor: City of Palo Alto AECOM 2 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 51  Packet Pg. 54 of 57  Connecting Palo Alto Table 7. Churchill Ave Stormwater Summary [A][B][C][D][E][F][G] Total Roadway Pavement Area Total Vegetated Area Total Pedestrian and Bicycle Pathway Pavement Area Railroad Ballast Cw Total Construction Extents % Change from Existing Runoff Volumes=Casphalt*([A]/[F])+ Cvegetated*([B]/[F])+ Cconcrete*([C]/[F])+ Cballast*([D]/[F]) =A+B+CAlternative ((‐) = reduction (+) = increase) (CAsphalt = 0.95) (sf) (CVegetated = 0.20) (sf) (CConcrete = 1.00) (sf) (CBallast = 0.70) (sf)(sf) Underpass 101,840 24,520 33,390 0.845 0.763 159,750 5.1% Closure with Mitigations (Option 1)7,062 9,390 16,676 33,128 ‐5.0% Closure with Mitigations (Option 2) Viaduct 10,992 11,820 17,266 0.750 0.657 40,078 ‐8.4% ‐6.1%126,000 168,000 294,000 Underpass (E)102,764 15,824 32,690 6,637 24,296 10,239 0.804 0.803Closure with Mitigations (Option 1) (E) Closure with Mitigations (Option 2) (E)24,362 4,351 8,808 0.819 0.700Viaduct (E)168,000 PreparedFor: City of Palo Alto AECOM 3 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 52  Packet Pg. 55 of 57  Connecting Palo Alto Table 8. Meadow-Charleston Stormwater Summary [A][B][C][D][E][F][G] Converted Property Acquisition 75% Ped/Bike Pavement 25% Vegetated Area Total Roadway Pavement Area Total Vegetated Area Total Pedestrian and Bicycle Pathway Pavement Area Railroad Ballast Cw Total Construction Extents % Change from Existing Runoff Volumes=Casphalt*([A]/[F])+ Cvegetated*([B]/[F])+ Cconcrete*([C]/[F])+ Cballast*([D]/[F]) =A+B+CAlternative ((‐) = reduction (+) = increase) (CAsphalt = 0.95) (sf) (CVegetated = 0.20) (sf) (CConcrete = 1.00) (sf) (CBallast = 0.70) (sf)(sf) Trench Hybrid 237,000 1.000 0.919 0.657 0.962 237,000 42.9% 3.4%20,503 46,781 129,602 159,233 8,130 72,000 3,370 22,193 96,000 118,740 159,925 168,000 281,343 Viaduct ‐6.1% 29.0%Underpass Trench (E) Hybrid (E) 232,000 100,000 0.700 0.889 0.700 0.746 20,503 46,781 124,588 116,450 8,130 22,193 84,153 Viaduct (E) Underpass (E)75,384 PreparedFor: City of Palo Alto AECOM 4 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 53  Packet Pg. 56 of 57  Connecting Palo Alto 2. References 1 “Analysis of pavement surface heating in urban areas.” Journal of the Croatian Association of Civil Engineers, vol. 64, no. 2, 2012, pp. 127–134, https://doi.org/10.14256/jce.641.2011. 2 “Cool Walls.” HEATISLAND, heatisland.lbl.gov/projects/cool-walls. Accessed 30 Nov. 2023. 3 “The Sky above Us.” NASA, NASA, pwg.gsfc.nasa.gov/stargaze/Ssky.htm. Accessed 30 Nov. 2023. 4 AzariJafari, H., Kirchain, R., Gregory, J. “Mitigating Climate Change with Reflective Pavements.” CSHub Topic Summary. 2020. Volume 2020, Issue 3. PreparedFor: City of Palo Alto AECOM 1 Item 1 Attachment D: Heat Island Effect and Storm Water Runoff Analyses        Item 1: Staff Report Pg. 54  Packet Pg. 57 of 57