HomeMy WebLinkAboutRPT 2 ACCIDENT SURVEIL 02-05-90DATE: JANUARY 17, 1990
TO: WILLIAM HUSTON, CITY MANAGER
REPORTS N0. 2
f2-5-90
Inter - Com
FROM: PUBLIC WORKS DEPARTMENT/ENGINEERING DIVISION
SUBJECT: KEY INTERSECTION ACCIDENT SURVEILLANCE
RECOMMENDATION:
Receive and file.
BACKGROUND:
The attached memorandum from the City's Consultant Traffic Engineer
outlines the monitoring that is performed on various intersections and
other locations throughout the City on an on-going basis.
This memo is provided for the City Council's information and no action
is required on this -item.
Bob Ledendecker
Director of Public Works/City Engineer
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Inter - Com
DATE: January 15, 1990
TO: Bob Ledendecker, Director of Public Works/City Engineer
FROM: , Jerry Crabill, Consulting Traffic Engineer
SUBJECT: Three Year Accident Tabulations
This memorandum is intended as information to you concerning the level
of accidents at key intersections in the City. While we do not have
the capability at this time to monitor all 71 City -maintained
signalized intersection locations, we have, however, monitored 16 of
the more accident prone signalized intersection locations in the City.
These 16 signals are situated in the older part of town and cover heavy
volume streets like Red Hill, Newport, Fourth, and McFadden. The reason
we have "tracked" these on a monthly basis locations is to identify
accident patterns from which accident reduction measures can be
evaluated and implemented.
In 1987, the accident tabulation for the 16 intersections amounted to
)5 total accidents, In 1988, however, the total fell to a value
164. This represents a drop in all accidents of about 20%. This
was indeed a significant improvement when considering City growth
during that time. In 1989, total accidents amounted to 156. This
represents a drop from 1988 accidents of about 5%. Again, recognizing
the large growth of the East Tustin area and especially the new
roadways that now further link Tustin with areas east of the City, such
an improvement in the accident picture is significant.
Please be aware that it is for the above reasons of accident reduction
that we sometimes pursue less popular solutions to verified inter-
section problems. Recognizing that large sums of money and possible
life-long injuries can result from just one accident, it has been, and
always will be, our policy to place the safety of the majority of
drivers over the complaints of the few.
A typical example of the above concerns the Irvine Boulevard
intersection with Elizabeth Way. In 1987, there were 10 accidents at
this intersection followed by 6 in 1988 and 11 in 1989. For 1989,
however, 9 of the 11 accidents occurred before the City implemented a
rather unpopular measure to mitigate the situation. This involved the
partial prohibition of eastbound left turns from Irvine Boulevard to
northbound Elizabeth Way. Specifically, the left turn prohibition
covered the peak hours between 7:00 to 9:30 in the morning and 3:30 to
6:00 in the evening. Although that decision by the City was unpopular
ffor a short while), it nevertheless yielded the following results.
'ter the installation and up to this point, there have been only two
.%,cidents. Again, prior to that point, there were nine accidents.
Bob Ledendecker
January 15, 1990
Page 2
The reason the measure was unpopular was its effect on the businesses
situated at the intersection on the north side of Irvine Boulevard.
However, they did eventually accept our explanation in that not only
did the restriction cover just a short time period of each day, it
also substantially reduced the volume of accidents.
There are other high -accident locations in the City where mitigation
measures aimed at reducing accidents will be implemented in 1990. The
most significant changes in this regard will involve modifications to
several signals. Specifically, all the intersections that currently
operate under the older "permissive -protected" left -turn type of
operation will be changed to "protected" left -turn operation. In
other words, the permissive left -turn which uses both the green
indicator and /or the green arrow (i.e., left turns can move through
available gaps in opposing through traffic volumes) will be replaced
.with "green arrow only" operation (protects left turns by stopping
)posing through movements).
We will of course continue to track the operation of these and other
locations during the year. We will provide you with another update in
early 1991.
J ry ab i 11
onsulting Traffic Engineer
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