sr-091669-8cCITY OF SANTA MONICA
IHTER-DEh1E T
DATE: September 10, 1969
TO: Perry Scott, City Manager
FROM: Bartlett L. Kennedy, City Engineer
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SUBJECT: Traffic Study, California Avenue at Chelsea Avenue
In compliance with instructions of the City Council (Item 7-C, meeting
of August 12, 1969), a study has been made to determine whether four-way
stops and marked crosswalks are needed at the subject intersection.
Attached is a copy of the Traffic Engineer=s report, recommending against
the installation of both stop signs and marked crosswalks, Iiis report
may be summarized as follows:
(1) Four-way stop signs
(a) Both vehicular and pedestrian volumes at this intersection
fall far short of the number prescribed in State of California
warrants for stop sign installation,
(b) Police Department records of the four accidents occurring
at this intersection since January 1, 1968 show that all four
involved eastbound and northbound vehicles, indicating the
cause was failure to yield right-of-way, .not obstruction of
visibility. ~i
(2} Marked crosswalks
(a) The extension of every sidewalk across an intersection is a
legal crosswalk, whether marked or unmarked. A painted
crosswalk conveys a false sense of security on the part of
the pedestrian and increases the accident potential. Studies
conducted in San Diego show that the accident ratio, between
painted and unpainted crosswalks, is 5.7 in painted cross-
walks to 1.0 in unpainted crosswalks.
It is the recommendation of the Traffic Engineer, concurred in by this
office, that the installation of stop signs and painted crosswalks at
this intersection is not warranted and would cause undue inconvenience
to the great majority of motorists using these streets.
~_
BARTLETT L. KENNEDY
City Engineer
Attachment: Report of
Traffic Engineer
CIiY OF SA~EiA t~A~t7!C.~
cv. a ~; i3 &`i " E~ ai 3' L~° S ~ ~ Q :i r ~:j ~ ~ ~ ~z H'~a 1°+~
D~r'aTL: September ?., 1969
TO: City Engineer
Fil~7~: Parking & Traffic Engineer
SUk3JEC'.Y': Traffic Study, California Avenue at Chelsea Avenue
We have conducted an investigation of the subject intersection to
determine whether 4-wap stops and marked cross walks we:ce needed
at this location.
This investigation included -
1. a 9-hour. manual count {See Attached Addendum I) to determine
.vehicular turning motions, pc-destrian volumes, etc. In 9 hours
only 870 total vehicles from all four approaches we:te observed.
The attached {Exhibit A) stop sign warrants prescribed by the
State of California indicate that the rninimurn ~earrant for_ a 4-
way stop must be 500 vehicles per hour for 8 hours, or a total
of 4,000 vehicles. As you can see, the 9-hour total of 870
fal7_s far short of ther_equired 4,000 that must be rnet for-the
installation of a 4--viay stop.
The total pedestrian volurne at all 4 legs of the intersection
for 9 hours was 184 of which only 66 were children. Again,
referring to the attached warrants, combined vehicle and pedestrian.
volurne from the minor street {California Avenue) of at. least
2.00 units per hour is far from being met. i. e. The total
volurne of 4.59 {389 vehicles and 70 pedestrians) divided by
8 hours is only 57 units per home.
In 9 hours only 19 motorists approached the intersection at
approximately the same time. This represents only 2.18 percent
of the total volume. Expanding this minute percent to 24 hour
volumes indicates only 35 motorists at best per day must use
cormnon.sense and observe the rules of the road, i. e. yield to
the vehicle on the right.
To install stop sign restrictions and compel the remaining
daily 1,557 motorists to come to unnecessary stops would be
extremely detrimental to the public interest. It would lead to
disregard for stop signs per se and ouite possibly result in
serious accidents.
2. a 5-day inbound to the inr.ersecti.on directional automatic
vehicular volume count. These counts show an average intersection
City Engineer -2- September 2, 1969
vo7_ume of only 1,592 per 24 hours, which is hardly sufficient. to
warrant 4-way stops.. It should be noted that vandalism particu-
larly by neighborhood children required our serviceman to effect
repairs to the automatic counting machines 26 times in 5 days.
3. an accident investigation study of Police Department records.
During the calendar years of 1908 and 1969, to date, only 4
accidents have occurred at the subject intersection. Each in-
volved vehicles east bound and north bound and indicate a
failure by the motorist to yield to the vehicle on the right.
Again state Gvarrants are not .met as they prescribe five accidents
suscepti:ole of correction by a 4-way stop in a. 12-month period.
In nearly 19 months only 4 minor accidents have occurred.
For your information we have attached (Exhibit B) a copy of an
article from Public Works Magazine of Aps:i1, 1909, on the feasi-
bility of painting cross walks. This study conducted by the City
of San Diego over a 5-year period shows that the accident ratio is
5.7 in painted cross cti~alks to one in unpainted cross walks.. This
study substantiates what we locally believed for a number of years,
particularly in view of the fact that we have had 21 fatalities in
mar;~ed crass walks over the past II years. In summary, it is our
recommendation based upon our study that neither 4-way stops nor
marked cross walks are needed at this intersection, contrary to the
petitioners' desires.
In fact, ?.-way stops should not be installed .because stop signs should
not be used as a speed preventative (See copy of warrant). ^1 he un-
regulated use of stop signs proves a hardship on tl~e community as
evidenced by the little usage of the D4illion Dollar street plants of
Arizona Avenue and Pearl Street wherein few motorists make use of
these streets because of the -repetitious use of stop signs along
them.
Finally, the greatest single fatal accident in my llz years experi-
ence with the City occurred this year wherein three people crere
killed at an intersection controlled :oy a stop sign.
,-~
;~ - ,
`J. J. Wrenn
Parking & Traffic Engineer
JJW:ns
Attachments - 4
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1~,, -, ,'r 1~ i~q
Part B-ircf'ec PLt`.t~!\ih~~ ;,R:,;'J'v.^,L ~-~f1?,l
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fs'-~F i3~S.3 CYEE=: IC3 ~ti3Y (_•i;? ~~f'p ET Y~ 'G~~..
(1) Design. With the e~,ception of the STOP and
Y1liLD signs, regulatorv signs arc rectau~`ular in
shape. Regulations that arc in efEcot at night are ordi-
narily posted ~i°ith roflectorircd signs. Signs in the
parl:iirg series, which inchrde nighttime regulations,
may be reflectorized. Plain signs are used for daytimc-
only regnlatimis. T_,laal: letters on a rrhitc background
arc used Sor all regulatory signs lvit-h the cieoption of
STOP, Y7ET~D and SPI+,'FD I,IP,II'l' signs, tho LANL-
IISIP CONTROL signs (R59 and h,GO) and most signs
in the parking series. -
(2) Lsr I?^gulatory si ns Are used to inform
motoris+~s of Le ulations whrch ~pph rt definite loca-
tions, specrfie tmres, or where thi re ulations are not.
self-eviaent. This group contains srgns regnlat.iug tlrc
movement, speed, stopping, or parking of vehietes.
Included among regulatory signs are some, like those
marking the end of a resri-ictect zone, that arc related
to operational emitrols, though not in thenrseh°os im-
posing any obligations oi• prohibitions.
The number of signs placed to infm~m motm~ists of
x regulation should be consistent with the need.
n_~~'i3.~ Criteei~ Pere t~4siri.^ra Ex2441 @,aca2[oI~
No specific rule case be gluon concerning loeatimrs
of these signs. iU:any nnist be. placed hr conformance
with legal regulations. Normally, they should be placed
u'herc trafc can sec 4rem in rotation to lire regulation
to which they refer. In rural areas, they should be
pnsit.ioued ou the right-hand side of the roa&way, at
least six feet from the edge of psvemcrt. The bottom
shall be a minimum of 5 feet about edge of paemncnt.
In urban areas and vherc parking' is prevalent, the
bottou of thesigns shall be. placed aC least ?feet
above the odge of paccment. Ou errbed sections the
edge of the sign shall bo a minimum of 12 inches back
of the curb face.
On freeways and clpressways, the edge of the sign
shall be 4 feet outside the edge of the paved shoulder
pr 2 feet bacl of the f-ce of the un•u on curbed see-
tlons Phe bot~m r of sI>u~ on frcen cys ehall normally
be 9 fe,t abort tle edge of tln prvcment. In inter
Lhange areas the clear hennht of srgns shall be flee
feet. (SceFignre 8-SOL2.}
`Pwo signs for different purposes facing the same
traffic should not normall'}' L•emonnted on the same.
post. The R'IR PEEP Rl:OIIT with the W27It., re-
flector and the tir?llR Lane. Reduction symbol with the
R63RDO \'OT PASS are esceptim{z to this rrile.
The follo;tidng illustration appears at the end of this
topic.
Figures 8-503.3A-One-way* Signs.
8-503.3I3-Typical Signing on Trecrvay
Ramps.
8-5<s3,~ }asi~:z. °ae sy ~Ie€.": 6.a~ci€~ra fc,: 1.;a's~ ¢;..a,°;3 ~ilj::s
eir,
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53'` 5^: its C ICSi Ms
AUTHORSI`L• Section 21353 of the Vehicle Code au-
thorizes Lhe Department of Public Work Lo erect stop
signs at any entrance to any State highway. Section
21.354 of the Code authorizes local authorities to desig-
nate any hrg'hwnl ender rtS jnrisdietimr a through
highway and to erect. stop signs at enhances thereto
or 8rey may designate guy intersection nutter their
exehtsive jurisdiction as a- stop intersection and erect
stop signs at one or more entrances thereto. Section
27.355 authorizes the instal7atimr of stop signs at any
location so as to control traiiie within an intersection
and it requires that stop signs be erected o~n both the
left and right side of a mre-way roadway which is; 30
feet or more in width where a stop is rei(uired at the
entrance to an intersection. It. also 7n•ovides that stop
signs shall not be installed at signalized intersections
and existing stop signs at such intersection shall be
removed not later than January 1, 1965. Seetien 31400
of the Vehicle Codc specifies Lhe shape, color, message,
and minimmn height and stroke width of the lettering
of all stop signs to be erected after January ], 1959
and itrequires that all such signs lie re iectorized, or
be illunriimted frori sunset to sunrise.
PO! ICY: USe the P1P sign on public r o rd at or
near the enhance to .ny 3n~n« I; or rntFr-.rc 'me
where a stop rs requncd or ~t ny Iocatron n:,.c;~~ry
to control traffic t rrh n an inter ~~ floe Z ne 30 2eaci~
sl~7r is t3te stauda-rti. siso awd t7.c rr~i,.ar?.Iasr for mill
rel~lricor,IOads o'r2 S'=nEe ;ra~leu=ays. The. 36-inch size may
ba used at problem locatierrs. `Phe.24: inch siUn n:ay
only he used mr two lane roads m- streets baring an
85 pcreentile speed of not. more. than 39 males per
hour.
All stops az'a.inst state highways must b ^.pproved
by }Ieadonarters_ In no ease shall S'10P sigrs be.
installed mr the through roadl;-ay-s of an expresss-ay.
Conditions warranting S'POP signs are:
1. On the less import tint road at its intersection
with a main road r;drere application of the
normal right of way rrile is uncinly hazardous as
evidenced by aeeiderrts susceptible of correction
by STOP signs.
2. On a county road or city street at its interse~-
tions with a state highway.
3. At the irlt:erseetion of two main highway`s. ^1he
highway traffic to be stopped depends on ap-
proach speeds, volumes, and turning movernerrt,.
''Urt o-Trof'lc PLliN~~ii1~G Ihtr"!'P,L 8_5nZ q~,
----•,-~--~.._ ~_~._e.„.,. _ ...-rte )canary 1, 1Y55
4. Or r sheet enteri~ig a le illy estzblis}red through correction include right angle and left turn col-
highlsa~' or street. lisimrs.
5. On a minor street where the safe. approach speed 3. bfinimum volmnc warrant:
to theitiieracctimt is lo_s tluui IO ntil~; psi hour
. a, The total vehicular ti~ohune enferino• the inter- °'?
h S1OP sign is riot a "erne !rl" and is nvta sub~~ sec~iolt fron al] approubes must tvcragc at --.
stitute for other tt attic. coots of d~-vices. lIanp timrs the ! least. 500 vehrclcs per hetu• fm~ any eighthours
need for t S 1OP stun cart b elnnwated tf t]?e sr ~ht ~ of an tiz,rage day, and
distance rv mcret.~rd b5 remo~-tu of stttuCtons. ~ ~ ~b. 'I`he combined aebietila~ and pelest2~iau col- ~~
The installation o7 STO;? sterns at locat]ons t here ; ttme from the minor street or htoh~s~ay must
the}° are nut :peeted m• where approach speeds ire 3 average at least 200 writs per hour fm• the
lush should be ~o del' if }~o~~sr' 1c bee~nse the~~ mtih
` same eight bouts, with an averse delay to `
tncrea,c «rtdeuts ~lotcev
~~,-t~Thcreisna ulte>'naYatie
~ minor street vchicrtlar traffic oL at least 30 --°'
to a~"1`Ll]5
si~n, f7ten au advattcc Codc l~'17R STOP seconds per veliiele during 4he masimuin hoar.
AIIli'~1D sign and appropriate. pavement marl.ittgs e. Virhen the S5-percentile approach sliced of the
should b~ placed in emtjunetion with it. major street traflic e~eccds #0 miles per hour
I nb.ic~t~ tluoagh the radio and press is highly ,
the mininuuu vchieuler volume warrant is 70
~~
desirable when STOP signs are installed xnd espe-
d
ll percent of the above requirements.
a
y when it is necessary to chaua~e their location.
Any of the foIlouing emulations may warrant a ~ four-~t~ay sYols sign installation is a useful traffic
four-way stop sign installation : eontiol measure when other available means cf control
~ ~
1. R here iraffie signals are warranted and the need ~ are not adequate. It s}tonld not be used unless the
volu
e
f t
ff
is nrg~ent, the four-way stop is an interim mews- m
o
ra
ic ou the intersecting roads is abort
are that can be installed grucicly to control traffic equal and is undesirable at lots-traflic intersections. "'~
while arrangements are being made for the sio tal t1 traffc sig,ial instal}atiou is tihe more satisfactory
solution
-
ntstallatimt' .
At a four-u~ay stop mtcrseetton eaeh•stop sign shall
j
~~
2. t1n ~ccideut problem, as indicated by five oa' moue be snpplernentcd by a separate plate mounted just
reported accidents cf a type susceptible oS cos- below it, reading "4-way" in black letterer on a white
reetimt by a four-way stop instaIlatimr in a 12- reitective background. The standard sire for such -
mmrth period. Types of accident, susceptible of plate is 12 inches by G inches. ~-''
_ ~ POLICY: Use t}te P21T sign to give notice of are- --
strieted prima facie speed limit. Ibis sign is available
for 2v, 30, 35", 4D,~~, 5Q 55 and GO mile per hour
_ limits and for 20 mile per hom~ trucl: )i~uiGs on
descending grades. (See Sectimt 8-703.) The minimum ~--°r~
sized R31, sign that sha11 be installed on a State
highii~ay is 36" ~~ 45", On freeways 43" s BO" signs
shall be used. The I?21,2 sign may be installed after
B2R(50) an cugineeriug and traflic etnvey has been conducted.
.
~ (See Section, ~~3b4 a]rd ~~358 of t} e Vehrde Code.)
--
'~ Secttmt 27.'Oo of the Vehu.le. Cone spcctfic ilv size
1 . ~ r~ ;~
of Iette,•s and numetils that ntt Ube used on speed _
~;
r i restrutton st~,ns iusi211 d ~.ftet J~nuar ], 19G-1. It •~
+ ~1„ ~ 6r],Pe GG es<r~k
„ aloo provides that the lctt^ta and acme ]Is nu such
/ ~ r ns
j
C n~ies E fe54e:~ Gres t and 2 signs sha11 he refleetorrzed, or i1}uminated from sunset
/
i t}
?, ~, 75' S- ] s C r~ ]e; als lien 3
~ (A!so urr ! -11
~
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innary I I9 U~ ;hall COllfOYtll t0 t-lIB now
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regttiremettffi or to the sticurorv requirements in elect
at the time the signs were crested.
LOCA71Oi~: Erect iu the standard pcsition on the right <,r
sheulder at the beginning of the restricted speed
~
zone. ~hcir speed zones arc longer than one mile ''
~
;
iuterrnediate signs stay be posted at approsintate -~
lanile intervals. On freeways install follo~t~ing each
interchange or at approximate 1-mile intervals Zv}iere
interchanges are «~idely spaced, for three or more
- lanes in each direction, dual installations will be used. -
_ ~>
a.~oid ~:,;
«heal <,,
a cross..
pedc_....
harardnt
taken be
all cases
O';. io
ace c,!:r
pedestr
desire f
dents.
Which i
walk cr
It t.:,:
gttestior
emba r
~ROSSWALI~ ?nA~KIDIG in San
Diego, California, is not done
ezsually, as it is in many mmticipali-
ties. hx fact, for a crossiral!c to be
marked it must meet well a member
of weighted ~~-eu-ranfs: There must
he an iusu Hicicecy of adequate gaps
in velricaar tr,ffic; a substantial
pedestrian coluutc; relatively high
leaf is approach speed; zed other
measurable signifeznt ixt `1_uences.
With respecE to marked cross-
tratks, the Policy on Pedestrian
Grosso; alks stn±es:
~TThen justi;ied and properly lo-
cated, a marked pedestrian cross-
;caIl; mtiy call the driver's attention
to a high pedestrian P.rv or an un-
usual location: poutt out to the
pedestrian tF.e safest crossing path:
Ex4racts from ti12 City cf San Uiego Policy on Pedestrian Cressvralks:
"Live purpose of a marked crosswalk is to inform driezrs of a high yederb-iarz
/low or re: aausual crossir=~ locatiat, mid to grside pedestrlarrs by pr-ov:ding a
marked area in which to ero.rs.
By legal dejtnitior! there are tln'ee or more unnmrked crosswalks at every
nrtersectime. Thz City does not uornudly install n marl,'ed crosswalk across an
intersection nppraach xvhere more restrictive trafl5c conn'al devices are in use.
St+ch devices map include n-cfc signals, stop signs rend }'field slgru. /'Iowever,
a er~~ssvvntk ;nay he n!arkad at a coat; oiled intersection iJ an t:nnuo'ked crosswalk
mould not be clearly discernible clue to pearllar geomen~ics or other unusual
yh}~siad c-onditiae.
d marked midhlock crosswalk Wray be installed whoa wmranterl ar the heals
of soared 2ngineeri~rq judgment. 1'he length of block benveea the intersections
shoald Ge no less P,rcnc 1,000 poet. There must be a reasounble demmrd by
pedest; i.vns to cross within a carcemrnted m~ca no ,'ass tfrnra d00 feet from the
nearest intersection. Tl+ere rurst be a high pedestrim+ volrune generator nearby.
and limit pedestrian crossings to
speciCtc locations.
Unjustified or poorly located
marked crosswalks may ixtcrease ac-
cidat¢ h'equency by hxlling both pe-
destriatu and chscers alto a false
sense. of security; create general dis-
respect for all teal is control rtevices;
and result in uxmecessarily high
painting and mautrenancc costs to
tiro City.
That there is concern over the de-
sirability of znarhutg crosswalks in
San Diego is_ apparent. In fact, that
concern has resulted i~n a five-year
(Januer}> 1, 1963 to December 31,
1987) study to obtain factual dot-:,
regarding the rclatice ner.-~bcrs of
accidents that occur in painted and
unn.inted cross;vaPs, a study trkticl-:
has produced results that tvi11 be
surprising to many safety-minded
people. The study was bv.ed on ob-
servations made zt 4GG intex~ections
in the city, each of which had one
pautted and one unpainted crosswalk
across the major thoroughfare, and
on supplementary pedestrian volume
counts made at'ten percont of the
cressiugs during afternoon peak
hours.
There has existed for some time
a rliflerence of opinion among tech-
nical and non-techrtical people alike
as t.o the merits of painting or not
painting pedestrian crosswalk--
BrieSly, onesch;olof thought runs,
"If you paint a cross:~; a', k, the nmtor-
ist can mote easily see it and there-
fore tsil.e special precautions to
Onc c
when cr
is the p:
alcut a
IS Cnml
likely t
aariabi.
ferencr:
meets.
to n.:m
section _
"before
Bible tl
abler x
time:
1'C13teti
Banal d
To ,:
mutt+
critcnr
1) T
2} i
thai h.
p=e;ti c;
Bowie c
thatfo~
~.,
Fc
:d.
A;
Jr.
Jt
Ai
0
r.;
e
.C
- PCiRT'C tiunRUC o.,,. ,....,+ ,,,. ~. ~ri!;~
at;ool o ' r~ugitt x t r:, `If y-ou pant
`. acro~x~l~~~~aet~ur_~ura,~ngthc
pedestrian to p]nce hnnsclf in a
hazardous position undar the mis-
taken belief that the motorist v: ill hi
all cases stop."
Gbviously, bot7r schools of thought
are conca~ned wiih the safely o£ the
pedestrian and are motivatedby the
desire to reduce pedestrian acci-
dents. BuC the question reanains:
Which is safer? The p:ii^ted a~oss-
wallcor the unpainted crosswalk?-
It was in an cfinrt-to 2ns;ver this
question that the City of San Diego
etvbarked on the study.
S;rdy {'a;am~,ers
One of the diff~cuhies encountered
when concocting a comparison study
is the problem of maintaining equiv-
alent conditions. If one intersectimi
is compared against another, it is
]il;ely that a multitude of uurclated
variables will eater the pictures-di£-
ferenees in volume, turning ntove-
n~xen t¢, oricnta lion and environment
to nantc a few. If the same inter-
sectiou is compared to itszlf on a
"before" and "after" basis it is pos-
sible that other tmdetuctabie vari-
ables may occur with respect to
time: Shifiiag trallic pattents, un-
related weather condi @bns and sees,
sanest differences.
To keep the variables to a mini-
murn in this study the following
criteria mere adopted:
1) To use a single time period,
2) To use only thane int.crsocfions
that have one pztin ted and one un-
painted cross'.valk, both crossing' fl.e
same main thoroughfare, Ti:is means
that for all practical pmpos~ the ve-
n.:..lar tra!.,c ~• ocsL~g cacti painted
ct o,-_:. a'k ~~ould be ncu I} th~'sau~~
as the t~2~.. crows nr he corre-
.,pcrctmg t..pa,n±~ u' u~,<_s.~oik.
3) To nse only those crossv.-«11-s
CrOa9 ino thG nlaJ pT i~0[A' of ira~LC.
4) To rise only unsig;talized iuter-
scctions. -
5) To exclude school crosswalks
Srcc the yellow paint wed to define
thcry has poor nighttime visibility
characteristics which might affect
the study results.
-6) To exchide midblock cross-
walics.
7) To elclude any- intersection
having rmusual flow patterns, sight
disfaztce proliluns, or unusual gco-
mch-ics that cotdd allect the results.
In order to murimiz~ further the
effect oI chance variables, it ;vas de-
cided to obtain as large a sample as
possible and e_itend the observation
over as-long a period•as practical.
Therefore, a five-yc-af observation
period was established; and after
consicicrable research, 40G intersec-
tions were -found- ihat met the
criteria,
It was recognized that. a study of
accidents in painted and unpainted
ci~osswalls at the same intersectiot
u-ould be of questimrable value un-
less it could be related to the amowtt
of peel ~trian usages In other words,
if no pedestrians use a certain route
one would hardly et:pect any pedes-
trian accidents to occur.
Ili order to clarify this matter it
obviously would be desirable to have
Iicdes±rian volume counts ati each
cresswalk to con-espond with ±he ac-
cident history, Comprehensive pe-
destrian volume counts, however, are
very difFicult and expensive to ob-
taut. .ate a cc t. ~'is,c i+. ;-,s dc-
c.,i~d to m.,~_ __.,r:ple 1_~~~,L=-i_n
co tt~- at 40 of the -h;it ii e ^ciio:>;.
A fora--hour pcnod (2 p.nt. to
6 p.m.) r: es selected as provi cih;
the ~ rcatcst likelihood for peck:±;-fan
activity in terms of school children,
shoppers and workers being on the
street. This wou}d provide some
measure as to what e5dent, if ~~m}~,
pecies h-ians use painted and tm-
painted crosswalks at the same
intersection,
~f I: Cf.'i? ~i
Table 1 shows a record of pedes-
trian -accidents occurring in painted
and unpainted crosswalks arrangcci
by month and year. The total num-
ber of fatal pedestrriau accidents oc-
ew;riug in the 400 intersections dur-
ing the study period was 18 in
painted crosswalks and 3 in vn-
painted cross'wal}:s. This represents
a ratlo of G: 1. During the same
period the total pedestrian accidenu
(fatal and non-fatal) evas 17i in
painied and 31 in unpainted cross-
walks, aratio of 5.761.. The month
showing the highest five-gear ac-
cwnulation of accidents is December,
with 24 occurring in painted cross-
walks card 7 in unpainted crosswalls.
September shoeved a surprising rec-
ord of no pedestrian accidents oc-
curring in un};aimed cross;vall:s fm~
the five-ycarperiod. The study also
revealed that the highest incidence
of accidents teas bet;aocn 5 and E
p.m. (2o accidents) and. 6 and 7 p.m.
(23 accident,). rlll of these acci-
detas occurred in painted cross-
walks; ceriously, no accidents were
recorded in unpainted cross;val.is
during these hours. Th>_ unpainted
CCi.3IL' } ..-., /?.G Ci Gti?n5 !t3 t'.i rtflSfG (!F) Cfl~ (i:i!?lt's(CG lr~) 'tv l`v554'.'G 11'.c
htentit F'atalitios
Other Pedestrian Accident
s
~ -
5 Years 1963 1954 1955 106>-.~--- 19u7 ---~To ta!
January :.... . t2 0
~~~~-~ t5 2 ~ t:4 U M
- U M U
February ..... ,
"
...
1 0 4 1 4 0 4 0 1 0 18 3
March
~'~'~ ......
2 0
"~~~~~ 1
4 0
0 6 1 4 0 2 0 3 0
16
1
2 0 5 1 3 0 3 0 -17 1
April ........
May ......... 10 1 0 - 2 0 4 I 3 0- 2 1
12
2
........
June ..... ... 0 1 3 0 2 0 2 1 4 1 4 1 15 3
........ ......... 1 1 1 1 4 0 3 0 2 2 1 0 11 3
July ......
August .. 1 0
......... 0 2 2 1 2 0 2 0 1 0
7
3
Sept^<mber ... 1 0
.....
3 0 3 ~ 3 0 3 1 11 2
.... 3 0 0 ~ 1 0 4 0 2 0 11 0
October
November ~~~~ 1 1
~~~~~~~~~ 6 1
1
0
4 1
3 0
3
0
17
2
December ... 3 0 -
....
3 0 2 0 2 1 4 2 18 4
..... 3 1 6 4 6 0 2 1 7 1 24 7
Totals ....... .....~.. 1'8 3 32_ 7 35 8 42 5 34 5 _
34 _
6 -
177 -
31
PIILLIC WORKS for April, 7959
%1
25 I~ s
_--____L~_- -f
--- ----
20 ---- _ . .1 _ i_ __.-_
Morked
~ CrwsvaL'r>-
$.IS ~ ~
.__1.-
.
_. _
-
a I I I
10 ._ _ __ ~ __. _ ~ __ _
I i ;
~
a
a i
i ~ i~
5 --.f
I U marrt:d---~
111
!~~I1 1 I ' PJI 1
.~~..1- v t'r
M 6. a.m: N 6p.m. t,1
G1 ,"-IVE-YEt:R study of fC0 intcrscc-
tion^. showed this record of pe d¢sirian
accidents es n function o£ time of dny.
crosswalks shots-ed poak intervals at
ti to 7 a,m. (5 accidents) and 3 #o
9 p.nl. (5 accidents).
In the painted crossvallcs the
highs-sf ineicience of accidents was
on Saflu-da}=s (38 accidents); the
lowest incidence was on Tuesdays
(13 accidents). In the t.mpainted
crossw2,lics tllc highest incidence was
on 'Puesdays and Fridays (7 acct-
dents eadt)and the io:vest was on
TVednesdays (1 accident).
Table 2 is a record of pedestrian
accidents by age groupings. As might
be expected, the hi ;hest incidence
in both pairltecl and unpaintccl cross-
wall:a involves the eery young and
the very old. For example, the high-
est iltcidettce of- accidents fm• both
types of crosswalks involved persons
70 years oid and over, with 35 ac-
cidents in painted and 7 acci[lcnts
in unpainted crossu=arks. This was
followed closciy by the 5 to 9 years
of age group, with 20 accidents iu
painted and G accidence in tnpainted
crosswalks. There '~.vere, ho~.vever,
some surprising paradoxes found in
.the remaining age group records.
For example„ the GS to tg-year ago-
group was iucolved in 13 accidenks
in painted crosswalks and none in
unpainted cross~.valls. Similarly, the
25 to 44-;car age ;;1'oup showed
an involvanleat •ot ZS accidents i:r
painted crosswalks, but none in un_
n~:_, ~ ,it .d [. o ~c ill c _
O cr?tl t ccu'cnt t by i ~e-
~e le.l a~ 5 r It 1 It tc i uva,i tks
,0 1~D into tau ~,__,.[~1 .1 c._as a'.ks. This
ratio compares with ih2 nedesirian
vohttrs patios, based on sanlpung as
dc,cribed earlier, of 2.G persons
cxv_ing in d.c painted crosswalks
fo 1.0 crossing ht the tnpainted
crosswalks.
Concl r ~o,ns
The data tend to lndieatc that the
nm lbel of accidents in paiatect
et ossv:alks exceeds those in un-
paiuted crosswalks by an amount
greater than might be e::perted in
terms of usage, and mlgllt suggest
to some Gnat it t, vbvlously better
to lea e pedestltan cl ocsings un-
n arl,ed .than to bowel with paint-
ing even some of Ehent.
Donald O. Dobbins, Senior Traffic
1';ngmeet m the Of;ice of San Dtcgo's
City En ut cl hastens to point out
thaEthue ale obvious apphcpious
for croU,~alh markings at, lnid-
block locations atld at complex in-
tersections. He suggr-stn as well That
the data presented may adtually
show that it is @te pad; strivt rather
titan the painted crosstcalk that is
atfault, and that n-hat may be iu-
dicated'is aerogram to eshtcate pe-
destrians in using the same precau-
%iolis oil painted crossivalbs that they
employ on unmarked crossings.
Dobbins suggests, too, that better
standards for determining tchen and
where painted crosswalks should be
established may be needad, and that
better techniques for increasing the
visibility of pc~desh'ians, partic« laxly
at night, should be developed,
b~rrrrt7rfs }er i~urice[i
Cl•nsssvr:l's
As has liven noted, the City of
San Diego has a policy of not utark-
ing pedestrian crnsstvalks unless
certain hazardous conditions justify
the action. The following warrants,
based on a point syr;Yem cvah:ation
~. t:b12~ ~ ..~. it e:l~5'irl C.:i 3iGGi ~2n.'s
bl~ iy,;j@ ~YG?ljiS
Age Aiumber of Accidents
Group _-~ hlarked Unmarred
0-4 ... ........ 3 0
5-9 ... ........ 29 6
10-14 .. .......: 25 4
15-19 ... ....... 7 h
20-24 ... ....... 9 2
25-29 .... .....:. 5 p
3034 ... ....... 2 0
3539 ... ..:.... 7 0
40-44 ... ......_' 11 0
45-49 ... '....... 11 1
5054 .... ....... 8 3
55 59 ... ....... 6 2
b0-64 ..
.
.......
6 2
65.69 .. 1~ 0
...
70} .... ....... 35 7
Totals .. .'...... 177 31
incorporating gap time, pedestrian
vohmie, vehicle approach speed and
gc oral coed trans, are crnplovcd.
llecmeut lw toy and the inccsti-
~' ml r en tl act s opinion hate been
suhvrclinated to afford ma:cimurr ob-
jectivity iu determining crosswalk
needs.
The point system is based on
m~~tmum scol~ngs of 7.0 lioints for
°dp time and 5 points each for pc-
rl~stt tan volamc, app oach speed and
;,enctal conchtions. The minimum
warrant for the insttdlation of a
rlat: ed ewss~Falk is s ttisPted tti ten
t lo<•2tion t rtes 1G of more points,
one of v,hlch rust b for pede~htan
~ of cote.
Gap time tsnrrallt: This is based
on the number of txea.hle gaps in
tralTic flow (a usable gap is an in-
ter v=al between vehicles equal to or
e:ccecding fhe time required for a
pedestrian to etnss the street at four
feet per second) in a fie-e-minute
period. Scoring ranges fi'orn a maxi-
mum of 10 points for less-than one
gap per period down to 0 points for
five or more gaps per period. i'hc
above criterion is basest nn a one
Hour field survey cotuistirg of 12
five-minute samples. If a marked
or raised median at least four feet
wide exists, the roacbt=ay is con-~
sidered as twv separate roads,
Pedestrian vvluu:e warrant: This
is based on the total number of pe-
destriatu crossing the street during
the peals vehicle hour. Scoring is
from 0 for ten or less crossings to
a masinlu:n of 5 for snore than 100
crossings.
v'lpproach speed warrant: This is
based on observed approach spce[ls.
Scoring for this warrant is unique
hl that it provides 5 poitats for speeds
from 30 tp 35 mph and fewer points
for lower and higher speeds.
General conditions warrant: 'Chin
is based on consideration of such -
itentsas intersection layout, pedes-
trian accident history, vehicle turn-
ing rnovemeris, adjacent gtotulcls
and buildings and pedestri art gen-
erators. Values up to a rna_citllurn
of 5 points are assigned accordin,
to the judgment of the enginser.
If, when a survey. is eoalpleted,
the total point score is 16 or greater,
there is a wa_x'rant far a marh-ed
crosswalk. Otherwise, there is- no
warr:.:nt.
As is frequently the case when
stttdy data azt compiled new aria
of interest hlYC been rc~c'thd. It is
hepecl that o,~porttutiti~a for ftuthcr
study v: i11 be created and that the
perplexing probleat of prociditlg for
pedestrian safety- and eori~,•enience cn
busy city streets kill be resolved.
'~, i_~
%,
llr..7:,L~n:
5t'il (. il '.,-.
nod tS dt :.,.
ttlnlt S ,tan:
SCH.ii
~e the . r;:.
the right a'
IlOR 85 ^C
imegrity,
function
S'nlce the :
cross m' o
way a[fecC
lion alld s
_-slmh ogee
thori.cd, 1
way Depa
~ gcees of a
tir_s dcl;cl
lation Vi -
lions may
ferent feel
~ high vacs.
i il:evds
degrees: o:
tics on pu
a!'e subjc
~~~ state to s
lions.
~'. tlsidc _.
'. posed b~
chines, :'< .
codes, d,
C811 all(:
fortuity
meats.
and rati __,
nlodatin`
of vary
3 iSfa. r.CC
partlrfeu
The fc
pOSed ';
Deparr„
tion, de
'~, stalling,
', utilities
'~ 'I-he.=. ~.
!i rights o
tttiliF
pocJ
1 p tt ':_
p w t-!',
j gas, ea
che:nic:
i iion :..
i be ac^
Icca.sl
.,,