02-02-1999 - Review of Traffic Conditions on Vine Avenue from Glendora Avenue to Citrus StreetI
0
TO: City Council and City Manager
FROM: Public Services Department
Engineering Division
Memorandum
OA GENDA
ITEM NO. C-1
DATE February 2, 1999
SUBJECT: REVIEW OF TRAFFIC CONDITIONS ON
VINE AVENUE FROM GLENDORA AVENUE TO CITRUS STREET
SUMMARY: At the request of the City Council, staff reviewed the traffic conditions on Vine.
Avenue from Glendora Avenue to Citrus Street. This report of that review
indicates that the traffic conditions have either not changed from the recent
past or have improved somewhat.. Both speeds and accident rates are within
normal expectation.
BACKGROUND
Over the past three years, staff has been particularly attentive to the traffic conditions
on Vine Avenue between Glendora Avenue and Citrus Street. Of particular concern
was the speed of traffic and the number of north -south left turn- accidents at the
intersection of Vine Avenue and Valinda Avenue.
The speed surveys done during this time period indicated that the prevailing speed
exceeded the posted speed limits by more than 5 miles per hour. The Police
Department was kept advised of staffs findings and they continued a presence along
the street to encourage vehicle operators to observe the speed limits. Staffs .concern
was that the established speed limits require a recertification through an Engineering
and Traffic Survey at least once every seven years for the Police Department's
'continued use of radar enforcement on Vine Avenue.
Due to the higher than anticipated number of north -south left turn accidents during 1994
and 1995 at the intersection of Vine Avenue and Valinda Avenue, the installation of
stripped left turn lanes was considered. The installation would entail the loss of parking
for about 250 feet on each side of Valinda Avenue north and south of Vine Avenue and,
when queried, the property owners who would lose the parking were not in favor of the
installation.
A project was funded in the 1997-1998 Capital Improvement Program to widen Valinda
Avenue so that parking could be retained while providing room for left turn lanes as had
been done several years prior on Cameron Avenue at Valinda Avenue. This project was
to be the beginning of a program to do a similar widening at eight locations with similar
problems. The cost was estimated at $80,0100 per location and, at the time the plans
were completed for Vine and Valinda Avenues, the City Manager (Jim Starbird), directed
staff to attempt to find less expensive solutions to the problems. The immediate, least
costly, effortwas to .increase the times for the yellow and "all red" clearance times. In
addition, staff has been reviewing partial street widening to retain as much parking as
possible while adding left turn lanes at somewhat less cost than the estimated $80,000
per location.
ANALYSIS
Speed surveys were done during December 1998 on Vine Avenue and they indicate that
the prevailing speeds are within 5 miles per hour of the posted speed limits. Although
these results seem to be opposite to previous trends, we have encountered similar results
with most of our recent speed surveys throughout the City. Apparently, the tendency of
vehicle operators to significantly exceed the posted speed limits has been affected by the
enforcement efforts of the Police Department. Based on this change, staff has stepped
up the rate of completion of Engineering and Traffic Surveys so that radar enforcement
can continue for at least another seven years.
Also, as part of the review, staff examined the speed limit signing along Vine Avenue and
found that all the signs were properly placed. However, all of the signs were the standard
size (24" x 30"). As a result of this review, these signs will be replaced by oversized (36"
x 48") signs.
• . •
City Council and City Manager
Page Two
February 2, 1999.
The enforcement efforts of -the Police Department have had positive results. They will
continue their enforcement including the use of the radar speed trailer. -
In reviewing the accidents during .the last year along Vine Avenue, there were
unexpectedly no accidents except at intersections. Even without any other causation,
accidents are expected at intersections simply because there are potentially conflicting
movements. The number of anticipated accidents is directly proportional to the. volume of
traffic passing through the intersection. The anticipated number of accidents is based
upon the Los Angeles County Department of Public Works evaluation of typical
intersections throughout the county. The State Traffic Manual recommends that positive
corrective action be taken when the actual number of accidents is 60% or more above the
anticipated number of accidents. Historically in West Covina when the actual number of
accidents exceeds the anticipated number, the intersection is reviewed by staff to
determine possible contributing causes and corrective actions. ?
Only three intersections along Vine Avenue had an accident history during the last year
that warranted a closer review. The intersection of Vine Avenue and Azusa Avenue had
seven accidents of which six were "rear ends" and one was a "right angle". With the
volume of traffic through that intersection, the anticipated number of accidents is ' eight
and the incidence of "rear ends" is not abnormal due to the speed and volume of traffic on
Azusa Avenue.
The intersection of Vine Avenue and Lark Ellen Avenue had four "right angle" accidents.
The anticipated number of accidents is 5.5 and there is no indication of any condition that
may be subject to correction.
As indicated on the attached collision diagram, the intersection of Vine Avenue and
Valinda Avenue had six accidents of which two were "right angles" and four were "left
turns". The anticipated number of accidents is 6.5. and the six accidents are less then
previous years (see attached accident summary). The two "right angle" accidents
occurred during daylight with the weather being clear and dry. In one accident, a driver
was cited for running the red light based upon the evidence and statements from two
uninvolved witnesses. The driver questioned the operation of the traffic signal which was
subsequently reviewed by staff on three occasions, once with the driver, and found to be
operating as programmed. The driver has implied that staff changed the timing of the
signal after the accident to cover-up the cause of the accident. In the other "right angle'
accident, a driver admitted running the red light.
Three of the four "left turn" accidents occurred during daylight and one occurred at night
with the weather at the time of each accident being clear and dry. Two accidents were
with northbound to westbound turns and two accidents involved southbound to eastbound
turns. In one accident, the driver admitted making the left turn even though the view of
oncoming traffic was completely blocked by a truck waiting to make a left turn from the
opposite direction. In another accident, the driver proceeding straight made a. lane
change too close to the intersection to avoid the left turning traffic. In the third accident,
the driver admitted making a left turn even though the view of oncoming traffic was
blocked by a vehicle waiting to make a left turn from the opposite direction. The fourth
accident report does not include enough information to determine a possible cause of the
accident.
Of the. six accidents at this intersection during 1998, at least four were preventable by the
drivers involved. One was probably preventable and one cannot be evaluated. During all
.the accidents, the traffic signal was properly operating and "no unusual_ roadway
conditions" were reported by the parties involved or the investigating police officers.
Vine Avenue is a 40-foot wide, two lane collector,street with traffic volumes varying from
3,600 vehicles per day in the vicinity of Azusa Avenue to 4,400 vehicles per day in the
vicinity of Glendora Avenue. These volumes.are significantly less than the 22,800 vehicle
per day capacity of this street. The prevailing traffic speed is 40 MPH between Glendora
City Council and City Manager
Page Three
February 2, 1999
Avenue and Azusa Avenue where the posted speed is 35 MPH and the prevailing traffic
speed is 42 MPH between Azusa Avenue and Citrus Street where the posted speed is 40
MPH. Although Vine Avenue is a collector street, it also functions as a residential street
with numerous homes having driveway access directly from Vine Avenue. As such, there
is a dichotomy in interests of the vehicle operators using the street.
If Vine Avenue was classified as a residential street, traffic calming methods such as
roadway narrowing, cul-de-sacing, and limited access could be considered. However,
traffic calming serves the combined purpose of slowing speeds to 25 MPH or less and of
discouraging through traffic which should otherwise use collector and arterial streets.
Although, selected traffic calming methods could be used on Vine Avenue, the
disadvantage is. that through traffic which should use Vine Avenue would seek. out
adjoining residential streets so as to avoid Vine Avenue.
The City Council could provide direction to staff to consider reviewing the Circulation
Element of the City's General Plan to change,the classification of Vine Avenue from a
collector to a residential street. Since the General Plan is to be reviewed in thenear
future, the opportunity exists to review not only Vine Avenue, but also all other similar
streets such as Workman Avenue, California Avenue, Orange Avenue, Francisquito
Avenue and others. Once the street designation was changed, consideration. could be
given to a plethora of residential street treatments.
FISCAL IMPACT
There will be some costs associated with completing and certifying the Engineering and
Traffic Survey as well as continued monitoring of the traffic conditions on Vine Avenue.
The Traffic Engineering budget anticipates and includes these studies and monitoring.
ALTERNATIVES `
Staff routinely reviews on a citywide basis means to address high accident locations -as
follows:
• Annual identification of intersections exceeding the anticipated number of accidents.
• Review of field conditions for possible problems with sight distance or pavement
friction factors.
• Possible adjustments in traffic signal timings.
• Possible addition of traffic signal heads (indications) at about $9,000 per intersection.
• Possible increase in size of indications from 8" to 12" at about $8,000 per intersection.
• Possible installation of left turn lanes at up to $80,000 per intersection.
• -Possible installation of protected left turn phasing at about $75,000 per intersection in
addition to the cost of adding left turn lanes.
• Possible splitting of the phasing of a traffic signal to reduce conflicting movements at
a cost of about $20,000 per intersection.
RECOMMENDATION
It is recommended that the City Council receive and file this report. .
-�-�/0 1,h54",
Thomas M. Ma er
City Engineer
BY:
W. Collier
Services Director
ACCIDENT SUMMARY.
VINE &- VALINDA
TYPE
1994
1995
1996
1997
-1998'
RIGHT ANGLE
1
3
2
[LEFT TURN
6
6
4
3
4
REAR END
2
5
SIDE SWIPE
1
RAN -OFF ROAD
HEAD-ON
PARKED VEHICLE
TOTAL
9
6
8
8
6
TYPE
NO.
INJURIES
RA
RE
LT
ROR
SS#A6
TOTAL
6
VALINDA AVE. AND VINE AVE.
PERIOD .FROM DECEMBER 97 TO NOVEMBER 98 LEGEND
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