HomeMy WebLinkAbout0242.093.. 1;
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April 15, 1993
HONORABLE CITY COUNCIL
Palo Alto, California
Attention! Policy and services co:::nmittee
~TQP INTERSECTION SYSTEM UPDATE
Me~rs of the Council~
This report is the periodic update of the citY'..ride "Stop
Intersection System". This report includes an evaluation of seven
locations in response to requests for installation of stop signs
from citi~ens and the Parent/Teacher Associations (PTA) of Jordan
aild Palo Verde Schools.
BACKGROUND
The citywide "Stop Intersection system" We',S adopted by the City
Council several years ago (a map of the stop Intersection system is
available for reference in the Transportation Division office, 250
Hamilton Avenue, Sixth Floor). The construction of new streets j
changes in traffic patterns, and the need to evaluate safety and
respond tc citizen requests, r:ecessitates that the City Council
periodically consider ~hether to update the system.
Most cities in California use California Department of
Transportation (Caltrans) criteria (Attachment 1), to determine if
the installation of stop signs is warranted. These criteria
include review of traffic volumes and traffic accident history. In
Palo Altc, the justification for a stop sign on a local street is
based on:
(1) The Council-adopted ftGuard & Go" policy (installation of stop
signs at every other block to discourage through traffic from
neigl1borhoods) ;
(2) Caltrans criteria; or
(3) warrants adopted by the City Council in 1973 for installation
of traffic control devices near schools {Attachment 2}.
CMR:242:93
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The justification for a stop sign on a collector stree.,t. in. Pale
I.lto is based either on caltrans criteria or council-adopted
crite~ia for installaticn of traffic co~trol devices near schools
for safety reasons. The policy for ~_r.terial streets has been that
they should not have stop signs.
Staff rei:eives many requests to install or remove stop signs. All
such requests are investigated and evaluated using the. above
criteria. Aas a result of such invoestiqatior.s, safety improvements,
which diminish the need tor stop signs, are sometimes made (e.g.,
painting red curbS, trimming bushes; etc.).
While many residents in Palo Alto li.ke stop signs, stop sign
requests can be controversial because stop signs requir~ motorists
to stop clay and night, resulting in increased noise and air
pollution. Historically, staff has suhmitted to the Policy ~nd
Services cOmI!littee. those requests: (1) that staff supports and,
therefore, the request requires a COUncil resolution to install the
stop siqn; and (2) that are not satisfactorily resolved by staff.
The Policy and Ser~ic~s COffiIDittee forwards its recommendations to
the council.
CURRENT UPDATE
This report includes an evaluation of requests to install stop
signs at the f~llowing seven locations.
Exhibit
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2
3
4
5
6
CJoI.R: 242: 5)
LOcation
Ames Avenue/Rorke '~'ay
east and west legs
J".;or.narnplon Dri ve::
~ewelJ R0ad
Channing A verlut!l
Guer Road
Hopkins A venuel
Cedar Stre.et
Hamillon A venuei
w. Crescent Dri v t::
Sequoia A .... ~nuel
Madrono Avenu~
Request
Install stop signs
C'o RQrke
If'l~ta11 w,p signs
on Noriliampt;)n
Install stop sign5
on Channing
InstaIl stop sigru:
(1D Hopkins
Install stop signs
on Ramiltlln
Install stop sign;;
l)n Sequ(1ill
.&;g;1.,O_~
ln5.tai!
Do Not wl.111
Do Not Ir.sr.aJJ
lfL'itaIl
Do NOI Install
Do Not Install
4/15/93
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For each loc~tion, there ie an informational sh~et (Exhibits 1-6)
that includes a location map, intersection sketch, bZic)r.ground an,j
evaluatio~ infor~ation, and staff recommendation.
The stop siqn requests for Channing, Hopkins l Hamilton and Sequoia
have co~e from residents residing along those stre:ets, 'Who are:
concerned about reducing speeding. Stop signs, however. are no~
spe~d cor.trol devices. They are used to resolve right-of-\oI'ay
problems caused by an excessiv~ amount of traffic or accidents. No
conditions 'Warranting the addition of stop signs exist at the above
locations.
staff recognizes that drivers do slow do\m at stop signs to stop
and yield the right-of-way to other vehicles; however. a study
conducted in Palo Alto arid several other cities indi<';ates that
driver a t~avel as fast or faster at mid-block locations to make up
time lost at stop signs. In addi't.ion l the noise and air pollution
caused by vehicles increases because of stop signs.
There are no simple solutions to control speeding. CUrrently.
staff is working on the Waverley/Addison study, which may result ir.
staff recommendations to use techniques such as raised circles,
cbokers and other msasures (\lsing concrete and landscaping). If
these measures prove beneficial, staff ~ould develop guidelines for
implementing thei~ use on other Palo Alto streets. Staff is also
exploring the possible use of sorne simple, low-cost measures to
control speeding~ These include chokers and meandering or offset
center lines, using pavement markers and/or paint as shown on
Attachment ) ~
~NVIRONHENTAI. ASSESSM~NT
Installation of stop signs is categorically
California Environmental Qu~lity Act l and
necessar)~ .
9.tJMMARY OF RE<;OMMEtWA,:[IONS
exempt under
no assessment
the
;s
staff recommends that the policy and ServiCES CClIIJDittee recoll1mend
to the City council:
(1) Installation or stop signs on both the east and west legs of
Rorke Way at Ames Avenue, and
(2) Installation of stop signs on Hopkins Avenue at Cedar. St~eet.
Staff does not recommend installation of stop signs at the
following locations:
(a) Channing Avenue at Greer Road,
(b) Hamilton Avenue at West Crescent Drive,
(c) Northampton Drive at Ne .... ell Road, and
(d) Sequoia Avenue at Madronc Avenue
CI':R: 242: 93 4/15/93
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Based on the Committee's recommendation to the City Council, staff
will forwaro a re~olution to Council authorizi~g installation of
stop signs at the appropriate locations.
Respectfully submitteJ,
Ak .41? a.....--w 8
ASHOK AGGARWAL
City Traffic Engineer
KENNETH R. SCHREIBER
Director of Plan~ing and
Community Environ~ent
~
city Manager
Attachments: Exhibits 1 - 6
1. Calt£ans criteria for stop sign installation
:.2 ~ city council adopted policy for installing traffic
control devices in school zone areas
3. Sketch of traffic management techniques
cc: city/school ~raffic Safety committee
Roger Wilder, Principal, Palo Verde School
Bob Alvares, Principal, Jordan Middle School
John Griffiths Steve and Noel Beitler
Howard Wolf Dick and Florence Bilek
Hay Wong Florence and Jim McAllister
vick~t Green Trudy ar.d Jack Andresen
B~rbara CUll Fran and Joe Olexo
John Sebes Marion and O~mon Fox
Nancy Barry Jane Marcus
Don GanschQ'oo,' Lew Merrnelst_ein
Roy McCandles R. Squires
0!R:242:93 4/15/93
Page 4
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~EClUE5T
J-OR STOP
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RORKE WAY
E.~ST
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RORKE WAY
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AMES AVENUE I RORKE WAY
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Request: Install stop signs on the easterly and westerly legs of
Rorke Way at Ames Avenue.
Rec~ived fr~~: ?rA of Palo Verde Scho~l
Exist~ng Ccnd.itioI1s: As shown above, both legs of Rorke for!!'; a ITI
intersection W'ith AmeS I and both intersections are uncontrolled. Beth
streets are local streets.
Aralvsis: Although it is not essential for all intersections to be
controlled by stop signs, there are not many intersections in Palo
A.lto where one or more legs of an intersection does T.ot have a st.op
sign. These two IT' intersections ar~ close to Palo Verde Schoel and
are uncofltrolled. Field observations indicate that a large nuonber of
elementary school students cross both loegs of Rorke along ;tur:es. since
the traffic on Rorke does not have stop signs, not every vehicle
yields to cross tl-a:ffic on A"!'"les. Vehicles 'Were also observed cutting
the corner. Installation of stop signs on both legs of Rork€ at Ames
~ould provide an added el~ment of control and £nhance the safety of
students. A school crosswalk would be installed on the easterly leg
of Rorke at Ames, as part of this improvement.
Becornmendation~ Staft recoIfu,ends that stop signs be installed on both
legs of Rorke Way along Ames Aven~e.
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REOUEST
FOR STOP
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NORTHAMPTON I NEWELL RD
Request: Install stop signs on Northampton Drive at Newell Road .
.Received from: PTA of Jordan School
Existi..ng Condi tiODS: Newell is a collector-street. Northa:;.ptcr.
is a local street. Traffic on Newell has stop signs.
Anal.Y~is: The PTA would likE to have stop signs installed en
Northamptotl, to create a four-..... ar stop, because. some student
bicyclists do not stop at the Ne~ell stop sign. A large number of
middle school students on bikes were ooserved traveling on Newell
across Northampton. Not all of the students stopped at the Ne~ell
stop signs, but students 'W~re observed watching -(or side street
traffic and being cautio"..ls. In addition, the volume of traffic on
Northampton is low (about 10 vehicles -were observed in a 15 mi:?1ute
period) and traffic travels at relatively slow speeds:. No
conflicts or visibility problems were observed, and no accidents
~ere reported from January 1~90 to Sep~ember 1992.
Recommendation: Staff recommends that stop signs not be installed
on Northampton Drive at Ne ..... ell Road. Staff has discussed this
i::>sue with Jordan PTA representatives, and they are aware of
stafts! reasons for not recommen.ding stop signs on Northampton.
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STOP
CHANNING AVE I GREER RD
Request: Install stop signs on Channing Avenue at Greer Road in
order to help reduce speeding.
Received from: Mar-ion Fox and otheL' Channing residents
Existing Conditions: Channir.g Avenue is a collector street 'idth a
bus route. channing is a through street at this location. Greer
Road is a local street and has stop signs.
Analysis: Channing carries approximately 6,000 vehicles
and it is estimated that Greer carries approximately 1,000
per day. The traffic volumes at this intersection
sufficient to justify installing stop signs according to
criteria.
per day,
vehicles
are not
Caltrans
A review of the accident history from January 19B9 to september
1992 (45 mon~hs) indicates that two right-angle accidents occurred
(one in 1991 and one in 1992) at this location. Although right
angle accidents are susceptible to correction by installing stop
signs or improving visibilit)~, no visibility problems were
.ohserved, and the cause of both accidents was inattention. The
accident history does not indicate any substantial safety problems
that warrant installing stop signs.
Inith.l1Yl this request was received from Marion Fox who ex-pressed
a concern regarding speedi"g on Chan~ing. Staff respond~d to Mrs.
Fox's request in a letter dated December 29, 1992 (copy atta~hed).
Subsequent to Mrs. Fox's request and other Channing residents also
expressing concerns about speeding, a neighborhood meeting \I.'dS held
February 22 ~ 1993, to share information regarding variol.Js speed
control techniques, including road bU!!lp::;" chokers, stop signs,
postJng speed limit signs to be consistent with engineering
surveysJ etc. This meeting was att.ended by 11 residents and
representatives of the Police Ocpartrnent and Transportation
Division. Several residents present in the meeting 'Were not in
fAvor of installing the stop sign.
Since the neighborhood meeting, statf received and responded to
another letter from Mrs. Fox (see attached). Staff has proposed to
use low-cost traffic management strategies, such as chok.ers and
meandering or off-set centerl ines (using pavement rr.arkers or paint)
on Channing to help control speeding.
Some time ago, stuff measured the free flowing speed of traffic in
the 1900 block of Channing~ 'l'he 85th percentile speed 'Was 35.5
mph. More recently, ~e measured the sp€ed in the 1600 block of
Channing between Stanley Way and Heather Lane, cl03e to Alester
Avenue. Traffic on Channing at Alester has stop signs. The 85th
percentile speed was measured at 34.6. This supports study
findings that indicate that stop signs are not effective in
controlling speeds.
Recommendation: In vie~ of the above, staff recommends that stop
signs not be installed on Channing Avenue at Greer Road.
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T ransportalkn Divisia1.
o·
December 29~ ]992
Mrs. Marion A. Fox
1990 Channing Avenue
Pale Alto~ CA 94303
Dear Mrs. Fox:
Cityot Palo Alto
Dqx17trn<!tll ,,[Plmming and
eonvn'.<nity Emr£row?lenJ
This letter is in response to yo~r letter regarding
speeding in the 1900 block of channing Avenue.
The current po~ted speed limit Or', ch~t"lning j~ 25 !'C.ph and ... 'e
recognize that man,' driver::; are 'traveling close to 35 mph.
As shoilm below, it is not uncommon in Palo }..lto or other
cities ~or drivers to travel appro)(imatE:::ly 10 rnph abo .... e the
posted speed limit.
Posted 85th
Speed Percentile
Location. L~l<'it ~eed _
Matadero Avenue 25 35
Maybell Avenue 25 34
Covper street 25 34
Stanford Avenue 25 J 4.5
Channing Aver,ue 25 35.5
These data, as well as past technIcal research, studies,
and discussions ~ith other Bay Area co~rnunities indicate
that mos~ drivers {es perce~tJ tend to drive at speeds that
they consider safe. The top 15 percent of drivers may
drive at unsafe speeds.
The driver'S determination of ..... hat speed is appropriate for
a specific street includes little consideration for the
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P4lo Al te, CA 94Ja3
0115.329,2,'-20
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December 29, 1992
Page .2
posted speed limit. Major factors that deterrnir,e a
driver's perception at .. 'hat is a ~afe: speed include:
• th~ width DE the travel lan€5
• ~he number of travel lanes
• the presence or absence of p~rked cars {which appears
to be translated into che driverts percepticn of lane
width and physical enclosure}
• the amount of traffic
• the S't;.rface condition of the road· .. ·ay ('Wet or dry,
smooth or rough)
• sight distance and visibility (darkness, fog)
• the extent of ro~d~~y curvature
• the slope and length of grades
• the number of intersections
• built-up areas near the roachlay
• school zones, esp~cially when children are present
We have considered several options to control speeding in
the 1900 block of Channing as follows:
• .p",o"5"t~"tlJh".,-=,s"-p~€",,e,,,d,--"1"1"-'· rn i tin ~ ceo r dance \01 i t h m II En a i neE ring
and Traffic" surveys. q.n.9...mmprovide pol ice r_~.dar'
enforcel'Ttent
The current posted speed limit of 25 mph -:armot be
Enforced using rad~r, because it does not conform to
"Engineering and Traffic" surveys, as required by the
Califor~ia Vehicle Code, section 40802. School zones
are exe~pt and the Police Tr~ffic Tea~ does U5~ radar
on Channing in front of the school for speed
enforcement. Based on a recent speed survey conducted
by the Police Department, a spaed 1 irnit of 35 mph or,
possibly, 30 mph \o.·ould ha".,re to be posted in order to
use radar. Although this option could be pursued, tr.e
community at lar-ge has opposed raising t~"e speed limit
in the past.
• Install stop slgt'.S 9n Channing at Greo; __ t:
stop signs are not speed control devices. 'They are
used to l-esolve right-of-way pt"obler::s caused by
excessive amount of traffic or accidents. No
conditions ~arranting the addition of stop signs exist
at the intersection of Channing Avenu~ and Greer Road.
Drivers do slow down at stop signs and stop to yield
the right-of-way to other vehiclE:s. HO'..ever, a study
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Ms. Marion A. fox
December 29, 1992
Page 3
cond1lct.e-d in Palo Alto and several other cities
indicate that drivers travEl as fast or taster at mid
block locations than if stop signs ~ere not i~s~alled.
to make up the lost time at stop signs. In addition J
the noise and air pollution cdlJsed by vehicles would
increase .
• Police D€p~rtrnent enforcemen~~D9_education effort~
The effectiveness of a speed reduction program using
enforcement and education techniques is directly
related to the establishment of a very visible police
pre-senee. Such an approach may be successful, but
only as long as the police presence continues and will
be costly. ~evertheless, the Police Department does
provide periodiC police enforc€>_ment on Channing and
has received n~rnero~s calls acknOwledging their
presence. In addition, the Police Department sent a
letter to ~ver 50 residents asking if they would like
to meet ~ith depa~tment staff regarding their concerns
on Channing (copy ~nclosed}4 Based on their interest,
a meeting 'alill be arranged by 'tl".e Folice Department in
January 1993 .
• install speed bumps on Channing
Based on i! study c,! the :Hidto"m neighbort.ood, Council
approved a road bump program, throug!]. It • .'hich road bumps
can b-== ir.stalled on ~ resiaer;tial streets (SUbject
to meeting council-approved criteria). This criteria
includes demonstration of an accident problem
indicated by six speed-related accidents within a
three year period. The rationale. for considerIng
accidents is to differentiate between a demonstrated
problem versus a problem perceived to be caused by
speeding. Speed burr.ps are considered inappropriate
for collector and arterial streets for several
reasons, including the fact that they tend to diverc
traffic to local residential streets. Channing is a
colle-.:i:.or street and does not have a de:T:1onstrated
speed-related accident problem.
Controlling speeding has been a challenge for a long time~
There are a limited nUi'!1.bec-of 'Ways to control speeding.
Hm.,ever, most of them have several drawbac'ks~ and their
di~advantages outweigh the:ir advantages. These include:
rumble st.rips, which are noisy and dangerous for
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Ms: Marion A. Fox
December 29, 1992
Page 4
bicyclists; serpentine streets (~har.ging the shape of a
street so that it zig-zags), which is expensive and has
additional drawbacks; and traffic circles. Past studies
using some of these techniques are inconclusive. The
cities of Se:attle and Por-tland, ho'wcver ~ have installed
traffic circles {rOund raised islands) and chokers, and
have found that they reduce speoecing. We are curr.ently
reviewing this information and may suggest that the City
Council consider their use on waverley Street in response
tc concerns raised by residents there. We ~ould do this on
a trial basis to gain firsthand experience \olit~ these
traffic controls. If their use proved to be beneficial, ..... e
would develop guidelines (subject to Council review and
approval) for implementing their use on other Palo Alto
streets, includ ing Channing.
Thank you for bringing you~ concerns to our attention, and
we ~ish you a happy holiday season.
;;:U~q1d
ASHOK AGGp~~AL, P.E.
City Traffic Engineer
M:oe
cc: City council
Albert G. Lake
Lt. Kathy McKenna
April 8} 1993
Mrs. Mario!']. A. Fox
1990 Channing Avenue
T'di ISJO tA:a,'[)r.1sia"1 Palo Al to~ C~\ 94303
Dear Mrs. FOx:
CityofPaloAltQ
l?q.;urt7I'U:.7Jt,-,fPlmmmgmui
Com111l.4 nify t.mircnlmcni
This letter is in response to your March 8, 1993 letter
:regarding speeding or:: Channing Avenue.
Follololing }:'our earlier letter of November 11, 1992 regarding
the same issue. we responded to you on Oecemhe-_:: 29, 1992
(Enclosure 1). Subsequent to the above response. a
neighborhood meeting was held on February 221 1 993 in the
home of Mr. and "'.Is. Marcus of 1820 Cbanning Avenue. This
meeting was attended by approximately 15 pe_ople, including
¥.r. Fox. The issue of installing stop signs on Channing at
Greer Road was discussed in great detail. Hany of the
residents present were not in favor of installing the stop
signs, because of concern that driVers ~ould travel as fast
or faster at mid-block locations to make up for time lost at
the. stop signs. Nevertheless, I cOlD.initted to include an
evaluation of your stop slgn request for city Council
consideration in the upcoming update of the Stop Sign system
Report. The policy and Services COl:Il:reittee of the Cit~{
Council is tentati velv scheduled to discuEs this i tern an
"_pril 20, and ,,'0 w'ill keep you ir,formed.
In my last letter, I indicated the possible use of traffic
circles (round raised islands) and chokers (narroW'ing the
road section physically using concrete islands) ~ These
techniques are being evaluated in the Waverley/Addison
ne.ighborhood~ 80th of these techniquEs involve expenditures
that would require Council review and approval, and we .... ould
not recom.'Ilend their \.lse to the Council on a citywide basis
unless th~ir U3e proves to be beneficial in the Wave.rley/
Addison area.
Meanwhile, in response to r~guests ..... e have received to
cont.rol speeding, Ior'e have decided to select one or more
locations to try some low-cast traffic management strategies
th~t have not been tried in Palo Alto. These include ~lJch
z..:.cHarru11nnA\,-enue
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PaIoAl!c,CA. 9{lC3
4"3.325.25?C
415329 229:<F<D:.
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Mrs. Marien A. Fox
April a J 1993
page 2
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measures as chok.ers and :meandering T or off-set r centerlines
using pa.\tI:!IUent markers or paint (not concrete) T as s[>Q-.,;n iF".
the enclosed sketches. You !I'.ay 1 iJ..'.e to discuss this idea
with yo~r neighbors and let me know if area residents ar~
interest.2d in the installation of chokers using pavement
markers and related signing in the 1900 block of Cha~ning/ on
a trial :Oasis~
with regard to your observations about Line 86. the S3nta
Clal."a County Transportation Agency implemented service
changes in January 1993/ ~hich h3ve reduced the number of
buses traveling Channing during the week and on 'Weekends.
'L'hese changes were carried out iT. conjunction ... ·i th a 10
percent service redw;:~tion program countY\w'ide. The transit
district targeted those routes or segments of routes that
carried the f>:W'est passengers. The changes on Line 86
included eliitination of Sunday servica and reduced frequency
of service ~uring the week midd'=:j"s and on saturdays {buses
every hour instead of every 30 minutes). These changes may
ha'le helped to ameliorate the noise pollution concerns you
raised.
Sincerely~
ASHOK AGGARWAL/ P.E.
City Traffic Engineer
cc: Jane Marcus
Attendees of February 22, 1993 neighborhood I!".eeti r.g
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REQUEST
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Request: Install stop signs on Hopkins Avenue at Cedar
help reduce speeding and control a large volume of
r~sulting from Rinconada park.
Str-eet to
traffic,
Received from: Several area r~sidents requested installation of
stop signs on Hopkins during the Rinconada Park parking issue
neighborhood meeting.
Existing Conditions: This is a T intersection of two local
streets I with Cedar Street forming the T. 'l'raffic on Cedar has a
stop sign, ~hile Hopkins is a through st=eet.
Analysis: A review of the accident hist~ry from January 19S9 to
September 1992 (45 months) indicates that no accidents of the type
suaceptible to correction by installing stop signs were reported.
One Sideswipe accident involving a parked car attempting to
parallel park was reported in 1991. No visibility problems 'Were
observed. Weekend volumes may range from 2,000 to 3,DOO vehicles
per day on Hopkins, and approximately 1,000 vehicles per day on
Cedar. Traff ic accidents and volume data do not support installing
stop signs.
The existing stop sign installation on Hopkins is inconsistent ~ith
the Guard and Go policy for local residential stre~t6, because stop
signs do not exist every other block on Hopkins. Although stop
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.5igilS arl! not speed control devices, Hopkins is next to Rinconada
Park I 'WhiCh is visited by a large nu.t'.ber of people on the 'Weekends.
Installing stop siqns would help provide some control at cedar~ In
addition, it is likely that so~e driv~rs may choose Hapkins as a
short-cut, to avoid the traffic signal at the intersection of
Embarcadero and Middlefield Roads, through the Lucie Stern Center
p~rkinq lot. Installing stop signs on Hopkins at Cedar would help
discourage any through traffic passing through Hopkins.
Recommendation:
street~
Install stop signs on Hopkins 1wen'.le at Cedar
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REQUEST
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HAMIl.TON AVE
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~est: Install stop signs on Hamilton Avenue at West Crescent
Drive to help rEduce 5p~eding4
Rec~ived from: John Griffiths, Hamilton Avenue
Existing conditions: Both Hamilton and West Crescent are local
streets. Traffic on West Crescent has stop signs and Hamilton is
a tnro~gh street.
Analysis: !t is estimated that Hamilton at this location carries
approximately 1,500 vehiCles per day and west Crescent carriers
approximately 1,000 vehicles per day. A review of the accident
history from January 1989 to September 1992 (45 months) indicates
that no a.ccidents "Were reported. No visibility problems 'Were
observed 4 The traffic volume and accident data do not support
i~stallinq stop signs.
The nearest stc~ signs on Hamilton exist one block away
street to the east and at Lincoln Avenue to the west.
sign installation on Hamilton Avenue is consistent ~ith
Guard and G~ policy on local residential streets.
at center
The: stop
council ts
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The attached letter was sent to Mr. Griffiths on April 7, 1993 in
response to his request regarding controlli!'lq speeding within the
1200 block of Hamilton. This letter includes a discussion of stop
signs and other speed cO:1trol :neasures, includ l.ng a proposal to use
low-cost traffic management techniques. such as chokers or
meandering or off-set ~enterlines (using pavement markers or paint)
in the 1200 block of Hamilton.
Reco~@end~tion: In view of the above, staff recommends that stop
signs not be installed on Hamilton Aver.ue at West Crescent Drive.
•
Ailril 8, 1993
Mr. John R. Grifflths
Special Master
1755 Embarcadero Road, Suite 150
Palo Alto, CA 94303 ·0907
D<ar Mr. Griffiths:
City of PaloAlt9
Dep'lrtrM!l a(Plmming and
Commu .. ..u.·y tm~,.ormw.li
Tnis letter is in response to your letter regarding speeding in the 12'00 block of
Hamilton Avenue.
The current p.Jsted speed lmut on Hamilton is 25 mph. A recent speed suney
indicates that the 85th percefltile .speed on Hamilton is 31 mph. \Vhile a 31 mph
speed is higher t.ian the posted speed limit, a comparison of trav~i speeds cn
Hamilton with similar streets in Palo Alto, as shown below, indicates that it is root
uncommon for drivers to traveI approximately 5 to 10 mph,above the posted speed
limit
Posted 85th
Speed Percenti:e
Location Limit St't".,.d
Bryant Street, Lincoln tc Addison 25 32
Bryant Street, Lo..,,'eli to California 25 3i
Cowper Street, Embarcadero to Kingsley 25 32
Waverley Street, Embarcadero to Lincoln 25 31
In addition to the above, we have checked U1e accidents reported to t.1.e Pel ice
Department from January 1989 to September 1992 (45 months) within fr,' 120J block
of Hamilton. No accidents were reported during this period.
Earlier, Mr. Howard Wolf of Hamilton Avenue conta'::ted the Police Department with
similar concerns. Based Oil those: concerns, we posted fOlJr 25 mph speed limit signs
on Hamilton Avenue; and I underscaJ1d that the Police Department also increased its.
2S:J :-LunrluI1A vero..ue
F.O.AA102..."(i
Po.loAltt:l,CA9-l...~
415.329.2521)
415.329. z:.s:9Fax
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Mr. John R. Griffiths
April 8, 1993
Page 2
enforcemr:nt a<:ti .... ities in the area. The Cit), Council has adopted guidelines for
installation of rood blimps. Road bump~ were instaJied in the M!ct0wn neighborhood
.. of Palo AIto, and they have successfl'lly reduced speeds. en t.ltos.e streets. Road
bumps, l1oweveI. are not appropriate for all S.itutiliclflS. They have .a number of
disadvantages., including delay to emergency vehicles, potentia! diver.s.ior. of traffic,
increased noise, general inconvenience to drivers and an unaltr.lctive appearance
Therefore, to regulate me uS€-of road bumps, tt,e Cit)' has established criteria (-:..:opy
enciosed) that must be met in order [0 install them. Hamillon Avenue does not meet
the necessary cnteria to qualify for road bump instaJla!jon,
Reg3.fding installation of stop signs on Hamilton al West Crescent, stop signs already
eAist withir: approximately 400' and 600' of West Cre~ent at Center in the easterly
directior. and at Lincoln in the westerly direction, respectively. Stop signs are not
speed control devices. They are used to rc:solve right-of-way problems caused by an
ex.cess~ve amount of traffic or accidents. No conditions warranting the addition of
stop signs ex.ist at the i~tenection of Hamiiton and West Crescent. Drivers do slow
down at stop signs and stop to yield the right-of-wa)' to other vehicles. Howe\ler, a
srudy COndtKred in Para Alto and several otin::r cities indlcates that drivers travel as
fast or faster at rr.id-blocl. !ccations, to make up time lest 3.t stop signs. In addition,
the noise and air pollution caused by vehicles wou:d increase. Nevertheless, if you
wish to pursue the ~nstallation of stop signs, please call me at 329-2575; and we .... ill
include an evaluation of your stop sign request in the \Jpcoming update of the Stop
Sign System report, for City Council consiJel-dtion. The staff recommendation to
Council would be against installing stop signs on Hamilton Avenue at \Vest Crescent
Drive.
Controning s.peeding has been a challenge for a lor,s time. Aithcl!gh there are r:o
simple solutions, we continue to strive to find qWlck, simple and cost effective ways
to control speeding, The Cities of Seatlle and Portland have installed traffic circles
(round raised I$lands} and chokers (narrowing the road section physically using
concrete isla.rlds) and have found that they reduce speeding. Both of these techniques
involve expenditures tha: \~.'ould require Council review and approval. Currently. we
are working or. a Waverley Street neighborhood study t.1at r; • .:;.y result In a
recommendation for using circles, choke~, or other meaSLlres in that area. \ .... 'e
would do this 011 a trial basi:. to gair: fir~thand er.perience with tl:e<~ traffic cO[l~H)l
methods. If their use proved to b;e beneflcial, guiddines for imp1elTlt:nting their use
on other Pa.lo Alto streets. would be developed.
\Vhile speed survey data and accident hbtory do not indicate any signifLcant speeding
problem in the 1200 block of Hamilton, we are intercste.d in selecting one 0r Inore
locations in Palo Alto to try some ]ow<ost traftic management strategies that have
,
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t, t
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Mr. John R. Griffiths
April 8, 1993
P'go 3
not been ttied in Palo Alto. The~ inc-hIde such measures as chokers and meande:11lg
or o.F.-set centerlines, using pavement markers. or paint {nor concrete), as shown in
the enclosed sketch. YO'J may like to discuss this idea with your neigh!:>or~ and let
me know if area residents 21'e interested in the im-lallation of chokers or off-set
centerli.!'les and the rel~ted signing. on a trial basis, in the 1200 block of Hamilton.
On a slightly different issue, we have fO["IA.'alded a copy at" your c:her leiter,
regarding adopting the parkv,;ay, to Ca1trd11~ since the area you have-referenced in
your letter is under CaltraI1S' jurisdiction.
Th;t.'lk you for bringing your COrlcerm to our ar.erJ'ilon.
Sincerely,
J.; <; ""---'---~-o c_1
, I I
ASHOK AGGARWAL, P_E_
City Traffic Engineer
AA:oe
CC: City Council
Howard Wolf
Lynne Johnson
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r
REQW~Sl J
FOR sro? ~
MADRONO AVE
EXISTlNG
srop
w > «
~ a
OJ a w
(1',
___ Jaio
RECUESi
FOR STO~ ...
~
SEQUOIA AVE I MADRONO AVE
..t. 1 '..-11\' 510P
-I-l·.,."y ~~"1l
_1_ 3.""a,. s~op
_:_ " w~y s::;::
• 'T,,aft,c5''I,,,,1
~eguest: rnstall stop signs on Sequoia Avenue at Madrono Avenue to
h~lp reduce speeding.
Received from: Nancy Barry, Sequoia Avenue
Existing Conditions:
streets. Traffic on
through street.
This is a
Mad.:-ono has
T intersection of two local
stop signs and Sequoia is a
Analysis: r .. 'he intersection of Sequoia and Madrono is located on
the south side of the Southgate neighborhood. This neighborhood
'Was a subject of extensive traffic stUdies, including traffic
volume and speed issues in 1980. At that time, Castilleja street
was closed to traffic at Park Boulevard near the east end of
Sequoia, which provided sufficient relief to the neighborhood. The
observed traffic volumes and speed on Sequoia are very 10\11'. A
review of accident history from Janu~ry 1989 to September 1992 (45
months) ind.icates that no accidents 'Were reported. No visibility
problems exist. The tr-affic and accident data do r.ot support
installing stop signs.
'. ,.
The current stop siqn installaticn on Sequoia is inconsistent with
the Council's Guard and Go policy~ The intent of the CU3rd and Go
~licy waS to introduce time delays to discourage through traffic
from using local residential streets. Ho~ever, actions taken in
the early )'980s effectively preclude thro'ugh traffic from the
neiqhborhood. Thus, only residents use this street, except for an
occasional delivery truck. Installation of stop siqns on Sequoia
Avenue would be consistent ~ith the Council's Guard and Go policy.
Recommendation: Staff r~co~p.nds that stop signs not be installed
on sequoia Avenue at Kadrono Avenue.
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ATTACHMENT 1
• Muitfw.y STOP li"ns
The "MulHway Stop" instaJJ .. tion may be useft.1 3t IlOme
focationl. tt sr,ould ordinarily be used onry wh"re
til=-vol'.Jme or traffic on th9 intefMlctins m.IId!l is e~proll'
Imatllly eqt.lal. A traffic: contrCll slg n;a.f is m"'" stlti sfac;ory
fot' an Int.~c1:ion with • heavy volume-of trlrtre..
POLICY
Any 01 the folic-wing condition I ma~ warrant. multi
way STOP St;rl: i n~lIation:
,.. Where traffic lignar. ara warranted ar1"d urgently
needed, the rniJltiwa!; "'top rna)! be .. n jnterim
measure thllt can be installed quickly to control
traffic while ."..ngemsnt'l are bern; made fo~
the s.igrt.llllnstaILitions.
2. An accident problem.. III fndlC11t~ by five or more
reported .c:c:idenb: wlttlrn • 12 month period' of
.. type fiusceptfb!. to correctJon by • lI",ultiweJ'
nap rnltanatlon.. Such ilCC~.rrts Incl4lde ngohl
lind lefMum collis-ions ... weI! a. r1gt'lt-angle
eorlisions.
3. l'JnimLlm tnltflc voJt.lmea
,a; Tl'::a total vei"llcut.!ir volume entering ttle ir't!f:1"
&eetion from a II • pproechel!l mlolrrt .ve!!.;e at
least 500 \-ehlc'oea per hour fOf any S ,",ours of
lin .verl". day, Ind
{b] The c.on,blned vehicular and! pe-destrian
V(jlume rr;.m the mmor street or highwlllf must
.verag. at 1 .. 5t 200 unltl! per "Ol,:r for the
... me 8 hour&, wlth.n .veraQ'e delay to minor
street vehicular t,.ffic 01' .t klallt 30 seconds
per vehicle durin; the maximum "our, but
Ie) When tne 8S-~rcentlH!) apPro.tIc:h aP\Hd of
the major street traffic exceeds 40 miles ;..r
hour, the minimum ..,ehic'Ur.ar yoll.Jme warnnt
is 70 ptJf'Cent of the above l"&quirementL
.. . ,
ATTACHMENT 2
AN EXCERYT FOR srop SIGN JUSTIFICHlor; mOM TIlE CIT\' COlfl',CIL
ADOPTED WARRANTS FOR TRAFFIC COl'TROL DEVICES NEAR SCHOOLS
Recommendations and ~gn priorities w the City Manager aIlU;"Jf ilie Superintendent of the
'Palo Alto Unifled School District foe the applicatiun of tramC control dr:.vic:es. Th."_.Arlalys.\s of
!be Deed for ~1\)1IIL~ial protectiqn for j s.chool cro::,s_h~odS uoon the follQwing
L~ __ MS!Lmplioos:
a. The maxirm;;'l delay a child should ~ e:tpo:;.teJ to accept should be :10 greater than thiH
wrJch would be experien-:-ed if a tr.ifric oontrol signal, timt!d so as to pl,wid:! 1.'1 adeql.1ate
cro~illg: ill!erVal, were located at the crossirtg under st::dy.
b. Some fonn of device is eswnti.11 when lhe number of adequate gaps ill the traffic stream
du...ring the period Ille childler. are uS-ing the cro.ss\i,.aJk is less than the number of minutes.
[n thaI same period of time, That is, gaps lc1S fr~uent thar. one per minu!e represent
.a siluatior thai rna)' requir.e some form of waming or oonL-ol device Of measure.
Information developed from field '§tudies and measured against the \larious traffk: fXlntroi
device W3ml!lts -.vill determine the type of pr.1lectl\lc measure t.h,u ,"'ill be phy.sically
iilstailed or established at the crossing. Generally. lhe policy for tn~ iJ1stallation of these
devices is as follcws'
1. Types available
Slgns. and Markings
FLa.~hing Signals
Pedestn3l'1 Walkways
Variable Speed Zones
2. The abo"'e devices wlll be lmta!led at those school locations wherein the
coneitioo of traffic, 1.t .• speed, vohm;e, ~treet width and vehicle gap. haviIlg
beer. reviewed by an engineering sW'\'t!y. are fOUild 10:
a. Produce frequent and adequate \le"hicle gap$ .s'Jch lha~ pedes.trians may
safely Cf.QSS t.be ,!;treet W!lnOu! additionaj controls bo;:ing present.
h. Tile u['1obstr'J<ted s.ight distance 10 the ~rossy,:alk i.!. more than Lllal
sno\,vn for sr<>eds indicated:
2S mph
30 mph
35 mph
40 mph
170 feet
200 feet
235 feet
275 f~1
B. School pcdt':stria."l traffic contr{JI measures and dt':\llces
1. Types a\lailabJe
Pedeslri.;rn g fade separation
School safely patrol
Separated walkwa.ys
Stop iilter~t.ion
Trame signal system
TransponaLon
2. The foregoing ,on trol mea.su res asld de ... ices are to be con~idered whe" the
conditions of tF .. .ffic exceed those condillons fisted under warning de.vices
(non-<:ontrol measures).
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ATTACHMENT 3
l\ ]1 ) ---=zl) J \~
I b~ __ ~
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SKETCH SHOWING CHOKERS. MEANDERING.
AND OFF-SET CENTEFlLlNES