HomeMy WebLinkAboutItem 8.2 DwntwnIntersctMonitrngRpt
;r.: -
.!
.
.
CITY OF DUBLIN
AGENDA STATEMENT
City Council Meeting Date: April 24, 1995
SUBJECT:
Annual Traffic Safety Report and Downtown Intersection
Monitoring Report
Report by: Public Works Director Lee Thompson
EXHmITS ATTACHED:
/
1) ( / Traffic Safety Report from TJKM
2) (' Downtown Intersection Monitoring Report
3)./ 1993 Traffic Flow Map (Average Daily Traffic)
4) / Level of Service (LOS) Descriptions.
5) Accident Location Map to be displayed at meeting
6) A representative of TJKM will be present at the meeting to
present the report.
3)
Receive presentation
Direct Staff to make modifications as recommended in the
report; i.e., install additional signing at Dublin Boulevard
and Hacienda Drive and install No U Turn signs on Dublin
Boulevard east of Village Parkway.
Authorize Staff to present this report on a biannual basis in
the future except when significant changes have been made
in the roadway network.
RECOMMENDATION: 1)
-tJV" 2)
FINANCIAL STATEMENT:
There are two recommended physical improvements which are not
already included in an established Capital Improvement Project or
in standard maintenance practices. These are installation of
additional signing related to the Dublin Boulevard/Hacienda Drive
intersection at an estimated cost of $500, and installation ofNo-U-
Turn signs on Dublin Boulevard east of Village Parkway at an
estimated cost of$loo.
DESCRIPTION: In 1987, the City Council directed Staff to prepare a Citywide
Traffic Safety Report which would identifY locations that experienced a significant number oftraffic
accidents and make recommendations for possible means of improving safety at these locations. Since
that time, Staff, through the City's traffic consultant TJKM, has prepared the Annual Traffic Safety
Reports and presented them to the City Council. This traffic safety report is combined with a "downtown
intersection monitoring" report per the Downtown Specific Plan recommendation. Because of the
extensive consultant and Staff time involved in preparing these reports each year, Staffis recommending
that these reports be presented on a biannual basis from now on. Staffwill continue to monitor accident
patterns, and if safety-related improvements appear to be warranted during the course of the two-year
period, Staffwill take appropriate action at that time.
ANNUAL TRAFFIC SAFETY REPORT
Following is a summary of the information contained in TJKM's report.
A total of262 reported accidents occurred in 1994, 20 of which were injury accidents. There were no
fatal accidents. The total number of acCidents in 1994 is somewhat higher than the 1993 total and about
12% higher than the average of the three previous years, which was 233 accidents. The number of injury
accidents in 1994 is slightly higher than the 3-year average of 19.
The Institute of Transportation Engineers' Manual o/Traffic Studies recommends that any accident
within 100 feet of an intersection be classified as an intersection accident, while those further than 100
feet from the intersection be classified as a roadway segment accident. This method has been used for the
_________________________________________________________~~~____._______._________________w.~_____________________.~~~~____
ITEM NO. J , _<-
COPIES TO: TJKM
J9(J ~9d
~
.
.
purposes of this report with the exception that several rear-end accidents located further than 100 feet
from an intersection were classified as intersection accidents based on a review of the accident reports.
The same method was used in compiling this year's report as was used last year. Intersections and street
segments were selected which had incurred more than three accidents during 1994, and accident rates
were then calculated for these locations. The accident rate is a function of the number of accidents and
number of vehicles traveling the road segment or entering the intersection per day. TJKM's report
discusses the methods of calculation for determining accident rates for intersections and major and minor
roadway segments.
The resulting accident rates were compared with the State average, and those locations which exceeded
the State average were analyzed to see if changes could be made to improve the safety of the
intersections or street segments. Tables II and III ofTJKM's report identifY the locations for which
calculations were made and the comparative accident rates.
The philosophy behind using this method of accident rate comparison is that intersections and roadway
segments with high traffic volumes tend to incur more traffic accidents as a matter of course. An
intersection with a moderate number of accidents and high traffic volume would have a comparatively
low accident rate, while an intersection with few accidents but very low traffic volume could have a
comparatively high accident rate. For example, the Dublin Boulevard/San Ramon Road intersection had
6 accidents in 1994, and 60,700 vehicles per day entering the intersection. The accident rate at this
intersection is considerably lower than the State of California accident rate. However, the Stagecoach
Road/Amador Valley Boulevard intersection had 4 accidents in 1994, with only 12,900 vehicles per day
entering the intersection. The accident rate at this intersection is higher than the State of California
accident rate. Such an intersection may need more attention than a location with a higher number of
accidents and a high Average Daily Traffic number (ADT), depending on the types of accidents that
occur. The Average Daily Traffic is the average number of vehicles entering an intersection or street
segment during a 24-hour period.
Nine intersections and six street segments were found to have accident rates higher than the State
average. Following is a discussion of the conditions and recommendations for these locations. Accident
diagrams are included as a part of TJKM's report.
Intersections
1. Hacienda Drive and Dublin Boulevard: Of the five accidents that occurred at this intersection in
1994, two involved unsafe left turns from southbound Hacienda Drive to Dublin Boulevard and two
involved vehicles traveling westbound on Dublin Boulevard failing to stop at the stop sign. The
remaining accident involved a rear-end collision. TJKM feels that unfamiliarity with the roadway
contributed to the two westbound accidents. It is recommended that additional signage (Stop Ahead,
Intersection Ahead, pictorial arrows) be installed to assist drivers. Estimated cost afinstalling signage:
$500.
2. Village Parkway and Lewis Avenue: A total offive accidents were reported at this location in
1994. Three of these were right-angle accidents, one was a sideswipe accident, and the other was a rear-
end collision. . Three of the accidents involved vehicles that had just entered Village Parkway northbound
from one of the driveways to the south of the intersection. In two of these cases, the driver left the
driveway, failed to see the red light at Lewis Avenue, and struck a southbound left turning vehicle. There
are three different driveways from which vehicles may enter Village Parkway in this vicinity. Since all of
these are within 60 feet of Lewis Avenue, motorists existing from these driveways may concentrate on
northbound traffic (to their left) and not realize that the signal is red. Analysis of accidents over the three
previous years reveals a total of four accidents involving a vehicle exiting northbound from one of the
driveways on Village Parkway to the south of Lewis Avenue. No other accident pattern is present.
There are no recommendations for improvement.
3. Golden Gate Drive and Dublin Boulevard: Four of the seven 1994 accidents were rear-enders;
one involved a truck striking another vehicle while making an unsafe right turn. Two wide load trucks
struck the pedestrian signal head while turning right from Dublin Boulevard onto Golden Gate Drive.
The three-year analysis reveals a pattern of rear-end accidents. These are not uncommon at signalized
intersections and are usually attributable to driver inattention. It is recommended that the existing signal
poles be moved behind the sidewalk. This intersection will be revised as part of the Dublin Boulevard
Widening project and the problem resolved at that time. (No additional cost over and above funds
already budgeted).
Page 2
07() -90
.
.
4. Dougherty Road and Sierra Lane: This intersection currently operates with Stop sign control on
the Sierra Lane approaches; however, a traffic signal is under construction. TJKM's report indicates that
there is no discernible accident pattern; however, the traffic signal should reduce the potential for right-
angle accidents. No further improvement is recommended.
5. San Ramon Road and Silver gate Drive: Of the four accidents that occurred at this intersection in
1994, one involved a vehicle striking the pedestrian island at the northwest comer of the intersection, and
one was a hit and run accident with a vehicle failing to stop at the signal. There is no discernible accident
pattern at this intersection, and no improvements are recommended.
6. Regional Street and Dublin Boulevard: Of the eleven accidents that occurred at this intersection
in 1994, five were rear-end collisions, three involved left-turning vehicles, two were sideswipe accidents,
and one was a right~angle collision. Due to development on the southeast quadrant of the intersection,
traffic volumes have increased. The intersection is currently operated by a five-phase signal with
permitted left turns on the northbound and southbound approaches. Between 1992 and 1994, five
accidents involving northbound left-turning vehicles striking southbound through vehicles were reported.
This type of accident would be virtually eliminated through modifications to provide exclusive left turn
phasing on the northbound and southbound approaches. It is proposed that, as part of the Dublin
Boulevard Widening project, this traffic signal be modified to provide eight-phase operation. (No
additional cost over and above funds already budgeted).
7. Stagecoach Road and Amador Valley Boulevard: There were four reported accidents at this
location in 1994. One involved an unsafe turning movement, one involved very excessive speed, one was
a rear-end collision, and one involved a pedestrian being struck. Analysis of all of the accidents during
the previous three years reveals no discernible accident pattern, and there are no recommendations for
improvement
8. Donohue Drive and Amador Valley Boulevard: Five accidents were reported at this location in
1994. Three of these were rear -end collisions, and the other two involved bicyclists. Analysis of all of
the accidents at this location over the previous three years reveals no significant accident pattern, and
there are no recommendations for improvement.
9. Village Parkway and Brighton Drive: Four accidents were reported at this location in 1994.
Two of these were caused by vehicles failing to stop at the Stop sign. One of these was a right-angle
collision and the other involved a vehicle striking a fixed object. The other two accidents at this location
were rear~end collisions. Analysis of all of the accidents over the previous three years reveals a total of
four accidents caused by vehicle failing to stop at the Stop sign. The City of Dublin is eventually planning
to install a traffic signal at this intersection. This improvement should reduce the potential for accidents
of the type discussed above. There are no further recommendations.
Roadway Segments
1. Regional Street (Dublin Boulevard to Amador Valley): Of the three accidents that occurred in
1994, two involved vehicles turning left into driveways and one involved a loose animal in the roadway.
There is no discernible pattern over the past three years, and no improvements are recommended.
2. Amador Plaza Road {Amador Valley to Dublin Boulevard}: All three of the accidents that
occurred in 1994 involved an unsafe turning movement. There was no discernible pattern to these
accidents. Amador Plaza Road is fronted by many driveways. A two-way left turn lane is provided for
movements to and from the driveways. There are no recommendations for improvement.
3. Sierra Court (Trinity Court to Sierra Lane): Of the three accidents that occurred on this segment
in 1994, two involved unsafe backing and one involved an illegal turning movement. There is no
discernible pattern over the past three years, and no improvements are recommended.
4. Amador Valley Boulevard (Village Parkway to York Drive): There were a total of three reported
accidents at this location in 1994. Two of these involved bicyclists riding on the wrong side of the road
and colliding with vehicles exiting from driveways. The other accident involved an intoxicated driver
striking a fixed object. Analysis of all of the accidents during the previous three years reveals no
discernible accident patterns, and there are no recommendations.
Page 3
69(J"' 90
'.
.
.
5. Dublin Boulevard (Village Parkway to Clark Avenue): There were a total of six accidents
reported at this location in 1994. Five of these were right-angle accidents, and the other was a rear-end
collision. Three of the accidents at this location involved vehicles turning left from eastbound Dublin
Boulevard into the Big-O tire store. Another involved a similar left turn from eastbound Dublin
Boulevard into an unspecified driveway. Police Services has indicated that some accidents on this
segment have involved eastbound vehicles making U-turns in the vicinity of Village Parkway. Police
Services has recommended that No U Turn signs be installed for eastbound traffic. Although motorists
should be aware that U-turns are illegal in a business district, it appears that additional signing in this area
would be an appropriate reinforcement of that fact. It is therefore recommended that No U-Turn signs be
installed for eastbound traffic on Dublin Boulevard approximately 250 feet east of Village Parkway.
Estimated cost of improvement: $100.
6. Dublin Boulevard (Golden Gate Drive to Amador Plaza Road): A total of four accidents were
reported at this location in 1994. Two were rear-end collisions, one was a bicycle accident, and the other
was caused by an unsafe lane change. Analysis of all of the accidents over the previous three years
reveals that five of the eight accidents within this roadway segment were rear-end collisions. This type of
accident is not uncommon in a segment with significant queues and a large number of driveways. It
should be noted that this segment of Dublin Boulevard is planned to be widened to six lanes as part of the
upcoming widening project. The effect this widening will have on the accidents on this segment is
unknown.
DOWNTOWN INTERSECTION MONITORING REPORT
This program is part ofthe Downtown Specific Plan adopted in July of 1987. Five intersections have
been monitored annually since 1987. Turning movement counts were taken in February of 1995 during
the p.m. peak hour at the following intersections and with the following results:
Comparison of Total Intersection Peak Hour Traffic
Volume
San Ramon! Amador Valle
Dublin Blvd.lRe ional Street
San Ramon Road/Dublin Blvd.
Dublin Blvd.Nilla e P
Dublin Blvd./Dou hert Road
1993
3486
3034
5750
2973
4419
1994
3774
3370
5903
3089
4680
Since 1993
+8.3%
+11.1%
+2.7%
+3.9%
+5.9%
Growth Rate
vs. 5-Yr. Avg.
1989-93
+ 11. 7%
+3.4%
-0.3%
+2.7%
+9.3%
All of the intersections show traffic growth over last year, and all but one of the intersections shows an
increase over the average of the past five years. The San Ramon Road! Amador Valley and Dublin
Boulevard/Regional Street intersections show a significant increase over 1993 traffic.
Volume-to-capacity (V/C) ratios were calculated at each of the five intersections to determine the levels
of service (LOS) during the p.m. peak hour. TJKM's report includes a table which compares the past five
years. The summary table below compares 1993 with 1994. The V/C ratio at three of the five
intersections increased over 1993 levels. At the other two intersections, the V/C ratio decreased, while
the volume increased slightly. This is eXplained by a decrease in traffic volumes at certain critical
movements within the intersection.
Intersection Levels of Service (LOS)
(See Exhibit 4 for LOS descriptions)
San RamonRd./Amador Valle
Dublin Blvd.lRe ional Street
San Ramon Rd./Dublin Blvd.
Dublin Blvd.Nilla e P
Dublin Blvd./Dou hert Road
1993
vIe Ratio
0.68
0.67
0.86
0.67
0.77
1994
LOS
B
B
D
B
C
vIe Ratio
0.72
0.70
0.85
0.65
0.86
LOS
C
B
D
B
D
Page 4
5'1{)~9{)
.
.
The increase in traffic at the San Ramon Road/Amador Valley Boulevard intersection indicates an
increase in p.m. peak hour destinations north of the intersection. However, the increase has been
observed only over the past year and is possibly attributable to statistical fluctuations. The increase in
traffic at Dublin Boulevard/Dougherty Road is most likely attributable to the recent Dublin Boulevard
eastward extension. The eastbound through movement traffic has increased 136% over 1993 traffic.
Based on a comparison with the previous five-year average, the other three study intersections do not
appear to have statistically significant increased traffic volumes.
All five intersections studied are currently operating at acceptable levels of service based on the City of
Dublin's LOS standard of acceptability. Therefore, no level of service improvements are recommended
for any of the study intersections.
g:\rrajficlagsrsfty
Page 5
67d -70
.
.
TABLE OF CONTENTS
Page
INfRODUCTION .............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1
Accident Trends ............................................................. 1
Accident Rate Calculations . . . . . . . . . . . . . . . . . . . . . . . _ . . . . . . . . . . - . . - . . . . . . . . . . . . . . .. 1
Method of Selecting High Accident Locations . Intersections .............. . . . . . . . . . . . . . . .. 2
Method of Selecting High Accident Locations - Minor Roadway Segments .................... 2
Method of Selecting High Accident Locations - Arterials . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . .. 5
RECOMMENDATIONS ......................................................... 7
Intersection Traffic Safety Improvements ..... _ . . . . . . . . . . . . . _ . . . . . . . . . . . . . . . . . . . . . . .. 7
Hacienda Drive and Dublin Boulevard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .' 7
Collision Diagram 1 - Hacienda Drive and Dublin Boulevard . . . . . . . . . . . . . . . . . . . . . . . . .. 8
Figure R-l _ Intersection of Hacienda Drive and Dublin Boulevard. . . . . . . . . . . . . . . . . . . . .. 9
Village Parkway and Lewis Avenue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . .. 10
Collision Diagram 2 - Village Parkway and Lewis Avenue . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11
Figure R-2 - Intersection of Village Parkway and Lewis Avenue. . . . . . . . . . . . . . . . . . . . . . .. 12
Golden Gate Drive and Dublin Boulevard ......................................... 13
Collision Diagram 3 . Golden Gate I?rive and Dublin Boulevard ....................... 14
Figure R-3 _ Intersection of Golden Gate Drive and Dublin Boulevard .. - . . . . . . . . . . . . - . .. 15
Dougherty Road and Sierra Lane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . . . . . . . . . . . . . .. 16
Collision Diagram 4 - Dougherty Road and Sierra Lane . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17
Figure R-4 _ Intersection of Dougherty Road and Sierra Lane. . . . . . . . . . . . . . . . . . . . . . . . -' 18
San Ramon Road and Silvergate Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19
Collision Diagram 5 - San Ramon Road and Silvergate Drive ......................... 20
Figure R-S - Intersection of San Ramon Road and Silvergate Drive ..................... 21
Regional Street and Dublin Boulevard .' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 22
Collision Diagram 6 - Regional Street and Dublin Boulevard ............... . . . . . . . . . .. 23
Figure R-6 - Intersection of Regional Street and Dublin Boulevard ........ . . . . . . . . . . . . .. 24
Stagecoach Road and Amador Valley Boulevard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 25
Collision Diagram 7 - Stagecoach Road and Amador Valley Boulevard . . . . . . . . . . . . . . . . . .. 26
Figure R-7 . Intersection of Stagecoach Road and Amador Valley Boulevard. . . . . . . . . . . . . .. 27
Donohue Drive and Amador Valley Boulevard ................. - . . . . . . . . . . . . . . . . . . .. 28
Collision Diagram 8 . Donohue Drive and Amador Valley Boulevard. . . . . . . . . . . . . . . . . . .. 29
Figure R-8 _ Intersection of Donohue Drive and Amador Valley Boulevard . . . . . . . . . . . . . . .. 30
Village Parkway and Brighton Drive ............................................. 31
Collision Diagram 9 - Village Parkway and Brighton Drive ........................... 32
Figure R-9 - Intersection of Village Parkway and Brighton Drive . . . . . . . . . . . . . . . . . . . . . .. 33
r
,..
,
I
f'.~
i .r
r-."4
t
r ...
;
!
, '
l I
!
L.__
.......
I '
l
I
l.~
[
.
.
TABLE OF CONTENTS
Page
Roadway Segment Traffic Safety Improvements ....................................... 34
Regional Street between Dublin Boulevard and Amador Valley Boulevard . . . . . . . . . . . . . . . . . .. 34
Collision Diagram 10 - Regional Street between Dublin Boulevard and Amador Valley Boulevard 35
Amador Plaza Road between Amador Valley Boulevard and Dublin Boulevard ............... 36
Collision Diagram 11 - Amador Plaza Road between Amador Valley Boulevard and Dublin
Boulevard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 37
Sierra Court between Trinity Court and Sierra Lane .................................. 38
Collision Diagram 12 - Sierra Court between Trinity Court and Sierra Lane. . . . . . . . . . . . . . .. 39
Amador Valley Boulevard between Village Parkway and York Drive ..... _ . . . . . . . . . . . . . . .. 40
Collision Diagram 13 - Amador Valley Boulevard between Village Parkway and York Drive ... 41
Dublin Boulevard between Village Parkway and Clark Avenue. . . . . . . . . . . . . . . . . . . . . . . . . .. 42
Collision Diagram 14 - Dublin Boulevard between Village Pa:rXway and Clark Avenue. . . . . . .. 43
Dublin Boulevard between Golden Gate Drive and Amador Plaza Road .................... 44
Collision Diagram 15 - Dublin Boulevard between Golden Gate Drive and Amador Plaza Road.. 45
APPENDIX
Results of the Analysis for Statistical Significance
TABLES
I Traffic Accidents By Year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1
II Intersections with Three or More Accidents in a Given Year from 1992-1994 . . . . . . . . . . . . . . . .. 3
III Roadway Segments With Three Or More Accidents In A Given Year From 1992-1994 ........... 4
FIGURE
1 Statistical Analysis of Accident Data
.. . ... . . .. .. . . . .. . . .. .. . . . .. . .. . . . .. . . .. "II' . 01 .. . . . . .. . . . . .
6
.
INTRODUCTION
.
Each year the list of reported accidents within the City of Dublin is reviewed to detennine if there are
serious traffic safety problems that can be corrected. The following study provides a description of the
overall accident trends in the City, identifies locations where traffic safety is below average, and makes
recommendations to revise traffic control to enhance vehicle safety. The study analyzes accident reports
from the previous three-year period, 1992 through 1994. In summary, the 1994 traffic safety analysis has
found that:
I'.;'
. The total number of reported accidents has increased slightly over 1993 levels, and has
increased 12 percent over the previous three-year average.
. ,"
Six roadway segments and nine intersections were designated as high accident locations.
. Improvements werc identified at several intersections (many are already planned). All
other high accident rate locations were found to have current and standard traffic contrOl
measures, or are currently being improved.
Accident Trends
The reported accidents from 1994 were totalled by severity and compared to the previous accidents totals
for the years 1991 through 1993. The resulting accident trends are listed in Table 1.
Property damage accidents have increased over last year. Injury accidents have decreased slightly from
last year. The total number of accidents increased 12 percent compared to the previous three-year average.
Property damage-only accidents are 13 percent higher than the three-year average, while recorded injury
accidents increased by 5 percent over the three-year average. There were no fatal accidents.
Table I
Traffic Accidents By Year
Number of Accidents Three- 1994
Year
Accident Type 1991 1992 1993 Average Total
% Change
Property Damage Only 207 214 221 214 242 +13%
Injury 16 18 23 19 20 +5%
Fatal 0 0 0 0 0 N/A
Total Accidents 223 232 244 233 262 +12%
Accident Rate Calculations
\
---
The recorded accidents can be categorized as either intersection accidents or roadway segment accidents.
The Institute of Transportation Engineers' Manual of Traffic Studies recommends that any accident within
100 feet of an intersection be considered an intersection accident and any accident further than 100 feet
of an intersection be considered a roadway segment accident. Accidents were classified using this method
'--
IL.~_)
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 1
April 19, 1995
I
\~.._~
\-'
with one exception. severall-end accidents located further than 100 f~ advance of intersectinns
were classified as intersection accidents based on review of the accident reports.
;,..7.
,
t
The accident rates for roadway segments between intersections were calculated by Equation 1. The
roadway daily volumes were taken from the 1993 Traffic
Flow Map prepared by TJKM for the City. A number of
these daily volumes were updated with 1994 traffic counts.
The length of a roadway segment was interpreted to be the
distance (in miles) between adjoining intersections.
(Eq", 1) RoodNay 5.,,,,,,,,, RaU
Typically, roadway segment calculations are more
appropriate for rural settings where there are longer
distances between major intersections. When applied to short segments, the resulting accident rates can
be artificially high compared to State averages.
Accide1Jt Rt:lU- Acc:it1DrU x 1,000.000
ADTxMilux36S
For intersections, the accident rates were calculated using
Equation 2. The intersection daily volumes were taken as
the sum of each approach to the intersection. These
volumes were collected in 1993 and 1994.
Accident Rt:lU- Acciden:ts x 1.000.000
ADTx36S
(Eq". 2) lIu......tiOll R,..
The calculated accident rates were compared to the standard
rates published in Caltrans' 1993 Accident Data on
California State Highways. The Caltrans report contains standard rates based on roadway and intersection
characteristics such as geometrics, traffic control, and area type. One method of selecting study locations
for focused study is to analyze the ratio of the calculated accident rate to the Caltrans standard rate for
similar facility types.
Method of Selecting High Accident Locations - Intersections
f .
Table II displays all intersections within the City at which three or more accidents occurred within a single
year between 1992 and 1994. The intersections are ranked by the ratio of the 1994 accident rate to
Caltrans standard accident rate. Nine intersections in this list are considered high accident locations (at
which the average actual accident rate exceeds the statewide average rate. Collision diagrams, included
in the "Recommendations" section of this report, were prepared for these nine intersections.
i.
Method of Selecting High Accident Locations - Minor Roadway Segments
Table III is similar to Table II except that it contains data for the roadway segments. Again. any segment
where three or more accidents occurred in any given year between 1992 and 1994 is included. Ten
roadway segments were identified as having an actual accident rate higher than the statewide average rate.
Of these ten, three were considered high accident locations without further analysis:
Regional Street, Amador Valley Boulevard to Dublin Boulevard
Amador Plaza Road, Amador Valley Boulevard to Dublin Boulevard
Sierra Court. Sierra Lane to Trinity Court
The remaining seven segments. located on major arterials, were subjected to more rigorous analysis as
described below.
\
L
,
~__J
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 2
April 19. 1995
\,-.
.
Table II
" ,
Intersections with Three or More Accidents
in a Given Year from 1992~1994
Number of
Accidents
Intersection ADT '92 '93 '94
Hacienda Dr./Dublin B1.d 11,900 - - 5
Village Pkwy.;Lewis Ave. 16,900 1 2 5
Golden Gate Dr./DUblin Bl. 24,800 9 5 7
Dougherty Rd./Sierra Ln. 26,750 1 3 4
San Ramon Rd./Silvergate Dr. 16,850 1 4 4
Regional St./Dublin Bl. 33,900 12 5 11
Stagecoach Rd./ Amador Valley Bl. 12,900 1 1 4
Donohue Dr./Amador Valley Bl. 17,000 1 1 5
Village Pkwy./Brighton Dr. 15,450 1 2 4
Brighton Dr./Amador Valley Bl.e 11,050 1 3 I
San Ramon Rd./Shannon Ave.e 17,700 1 3 4
Village Pkwy./Dublin Bl.e 31,950 8 13 7
Dougherty Rd./Dublin Bl.e 46,150 18 9 10
Regional St./Amador Valley Bl.e 19,600 3 0 4
Amador Plaza Rd./Amador Valley Bl.e 22,900 2 0 3
Dougherty Rd./Amador Valley B1.e 23,625 6 4 3
Dougherty Rd./WB 580 Rampse 53,950 13 2 6
Amador Plaza Rd./Dublin Bl.e 29,850 6 2 5
San Ramon Rd./Amador Valley B1.e 32,250 9 10 4
San Ramon Rd./Dublin Bl.e 60,700 11 4 6
San Ramon Rd./Vomac Dr.e 21,300 0 4 2
Village Pkwy./Amador Valley Bl.e 33,850 6 2 3
Dublin Ct./Dublin BLe 24,450 2 3 2
Amador Plaza Rd./Dublin BLe 28,400 6 3 2
Sierra CtlDublin B1.e 26,750 4 1 1
.
1994 Data
Acc. Std. RatioC
Ratea Rateb
,"
1.15
0.81
0.77
0.41
0.65
0.89
0.85
0.81
0.71
0.25
0.62
0.60
0.59
0.56
0.36
0.35
0.30
0.46
0.34
0.27
0.26
0.24
0.22
0.19
0.10
0.50 :;::?H&(:30:
o 45 :.:.:.::%:.i'i:i~6:
~~~ Ii
0.70 :.:.:.:::::....f.t~~:.
.._....,..','.'.........,'N........
........'.'.',.........................
;.:. :.:.:.:.:':.:.: ':';':':'~':':':':'.
0.....'..12f
~:~O :\\\\\\l\\\\l\iiilj\l~\\
.....,.............
O. 71 ..:::~::::::::':1:[.OO::
.......0...'..,..,','.................
.,......."......,..
0.2S 0.99
0.70 0.88
0.70 0.86
0.70 0.85
0.70 0.80
0.45 0.80
0.45 0.77
0.45 0.68
0.70 0.66
0.70 0.49
0.70 0.39
0.70 0.37
0.70 0.35
0.70 0.32
0.70 0.28
0.70 0.15
a. The accident rate is measured in accidents per million vehicles for intersection.
b. Accident rates are categorized on the basis of facility size, configuration. type of
control and area density. All intersections are in the "Suburban" category.
c. Ratio = actual calculated rate/Caltrans' standard rate.
d. Only one year of accident data is available for Hacienda Dr./Dublin Bl.
e. Three or more accidents occurred at this facility in a given year but the facility's
average accident rate was below the statewide average.
!,
.;~--
;..~ ...I
,
.,.,
Page 3
April 19, 1995
1994 Traffic Safety Study
T JKM Transportation Consultants
i
'---
"-_n'
8
III
-
=
~
~
'0
~
<-.:r
Q,l'"
...'"
=~
~N
...'"
=~
t E
... f
~~
-= ...
:: a3
s:~
III =
- ~
= >
Q,l .-
~~
en =
....."""
~
eu
=
=:
s
o
'<t'
0'1
0\
....
'5~
... =
2~ ~
a 8
z<
,.l:
bh--:-
=.:::
~"-'
.
.
~
.c
~
~ .~~'!~~\5~u~\;:~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
~ <:;:):i :>>):::t:.::}~<:~:~.::\:::::
.:.:.:.:.:.:.:.:.:.:.:.:.:..~ ::::::::;~\:~;:<:::>::::::::::::.:.....:,:",
<I)
-5
.5
~
~
c
<I)
~
~
'0
e
~
B
r:
]
N
'"
000000000000000000
~~~~'<t'~'<t'~'<t''<t''<t'~~~'<t'~~~'<t'~
~,~__N~~~~~~~~~~N~N~~
CI)~
8~S~5~~~~~~~3~~~~~~~
<~
~
~M~~~~~~'<t'N'<t'M....N~-""O
i- ~
'0;; ~
~ ]
~ ~
'0
ij ~
....I "-" ""'" .-..I
= IU +-t c::
au r;; 5 ~
~ 'Ot:::
~'O 'g.s
... <<I.!:P
i;',8 <I)'"
~ E e> .?;-
"O=' <I)"@
e c. ~ .~
..... = <1)'=
..s:.g -5 5
-:';~ ...'"
~ ::l ] 0
'E ~ = ~
<) t:: a:s
u8 >.la
:c. c~
u ~ <1).-
> -- .~ ~u'"
'" bO <<I
g~ .~...
:.::~ BeC'l)
::: '0 r: .... :s
>. ...... E~ '0::;'...
-d~ ....... ...... lTl:=lO
iri. ~ ... ~ CQ 8. 0 -a '0 ""
~ 0 l3~" .... ~ iil <<l "'. ~ ~ .!a N.s 8
...... u .ill __ CQ c;: J:,o :::::; I: ~ '" .!a .=
"@;:: p.. ~ ~ 5 :3 .?" ~ <Q <) .3 -5 ~
::;;:~~>]~.grrca~ ~].s S'ag
Ol"><"g...o ClClP:::O'O ~'" ~'OC::
'0 - a .9 0 9 "'......,..... ,1:_ =0 <Q cO
dE~~<~E:ici~~dO~]] ~~~
,g ~ ~ u 9 a:: s ~ ~ '0 '" g S 5 ~ ::l'0 r: g c
'C o!)>' ~ ~ ci .g -d ~ p:: ~~ 9 iil ~ Vi ~ ~ ~ -g E :2
Iii f-< ~ >. "' ~ p:; 0 000 . 0 0 0 .~_ <<I . ~ <I) U
S < := ~ ca E t:: 00 II') ii!:3"': 9 .. u i:' B :sl a!
.S "~ > p.. 0 < ~ ~ CI) ,t;J U > f\) ~ -a 8 >1
~.5~~......<I)= a...Etl ";I='...<d~~BU<<I~
:S ,::; ~ CQ!:P ~ iil P::: ~ ~ ::;;: g Cl .:: 11 I'l ... '" ~ '"" <I) 0
..... ..... ,~ ~ ?....-:o t:: ~ B Ua <Q :S:a
~"' . ::;.. a '0 >. c . -d >. ~ -d :;J ... <<I E
~ >..::: >...::: > ," ..2 .'.J! :s p:: ..2 ~ p:; '" u"" .!OJ .g .... 'c u .S
<<I ~ tI) ~ - ....., """l ~...... _..... .... tI)....... ~ <<I ... '"
en ll:: ~ .10: ctl >- C <<I t:: U =.J::I II 0 ,...
ca .. ~ ~ ~ ~ ~ ~ 6 ii3 j' ~ ~ ~ ~ ~ ai .5 ;] j .~ ] i
.9 ~ ..s t: ..s <<I :0 :a "g ~ eI) 0:: '0 ~ p:; ~ :E ~ ~ < ;" p:; F <
E~:;~:;~oo~ o8~~Ci~o8~ cd.c u-d~
M~~MM_~__'<t'~~~~MOM'<t'
~
?'
_O'<t'~N~N~N~
~ON~-
MII')M
~
>
~~~~~~~~~~.~~~~~~~~.
~~~qll')~~~""OOO~~oooo~~"
...._~_~_~~~M~~M~~II')~-
000008~~0808880Il')08
a~~~~oo~~q~~~oo~~~~~
~ 'l""""'I '"""" ~ ......... ....-I .......,.,.....t......
f-<
~
~~~~~~~~~~~~~~~~~~
~~~~~~N~d~~O\o~~~~~
_ ...._~NN~'<t'~NN~~N
'5
E
bO
IlJ
tI)
'8
p:;
Iii
.5
:0
Iii :;J
c Cl
:a 9 d
:;;l >
Cl ii3 <r.:
.9 >..~
.....: ~ ~
J:Il'Ca,3
>>;> S
..2 6
ca~
> E
6 <C
"g
a
<
Page 4
April 19, 1995
1994 Traffic Safety Study
"T JKM Transportation Consultants
r-
I
I
Method of Selecting High Ac.nt Locations - Arterials
.
.......-.
I
For the five major arterials within the City of Dublin (Dublin
Boulevard, San Ramon Road, Village Parkway, Amador Valley
Boulevard, and Dougherty Road) a statistical method of analyzing
accident data was used. This method, presented in Highway
Research Record Number 188 (Highway Research Board, 1967),
is used to determine if a high accident rate for a roadway segment
is statistically significant or simply the result of normal fluctuations
in accident rates.
Control Limit = ^ :l: 1.96 ~
Wile'.
.. = avorall tJJ:cidofJI raU
III = VMI' 0" rood ..gflWll
(E,.., J) CalCJmiofl of controllilllil.
First. an overall accident rate (A) is developed for the entire length of a roadway. Then, upper and lower
control limits are calculated for each sub-segment of the roadway based on the vehicle miles of travel
(YMT) for that segment. Equation 3 gives the equation used to calculate the control limits.
If a roadway sub-segment's observed accident rate is greater than the upper control limit. the deviation
from the overall accident rate for the entire roadway is considered statistically significant (with a 95%
confidence interval). In other words, the segment is most likely exhibiting an abnormally high accident
rate and should be investigated for possible improvements. If a sub-segment's observed accident rate is
less than the lower control limit, the deviation fTOm the overall accident rate is statistically significant
(with the same confidence interval) and the segment is most likely exhibiting a lower than normal accident
rate.
Figure I illustrates the results of the control-limit analysis applied to Dublin Boulevard between Silvergate
Drive and Dougherty Road. The individual points represent the accident rates for the individual roadway
segments and the lines represent the upper and lower comrollimits. As the figure indicates. two segments
of Dublin Boulevard (between Golden Gate Drive and Amador Plaza Road, and between Village Parkway
and Clark Avenue) had accident rates that fell outside of the control limits.
~, -
Similar calculations were made for the four other major arterials in the City. The details of these
calculations are included in the Appendix. Three roadway segments were found to have significantly high
accident rates using the control-limit method. These are:
("
Dublin Boulevard, Golden Gate Drive to Amador Plaza Road
Dublin Boulevard, Village Parkway to Clark Avenue
Amador Valley Boulevard, Village Parkway to York. Drive
.... ."
Collision diagrams were prepared for these three segments and are included in the "Recommendations"
section of this report.
I"
\ ,I
\ '
,
L
i
I
I,
I. ~ .
!
)
'--"
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 5
April 19. 1995
r'-
I no'
~
--c
=
...
rJJ
~
......
~
e-d
rJJ
~
~
~
e-d
;.
~
~
0'.
0'.
~
\ ,
,
\....
~.-
, ,
, ,
, ,
, ,
:'
,
o
o
o
o
,......t
,
..
0 .-
0 ~ E
0 .,j.j .....
CI) ~
- 00 ~
-
0
I '-
..
CI) c
.,j.j 0
C'd U
OJ)
;..... '-
0 CI) ~
o >- :::
0:-;:::: 0
\DC/) ..J
~ I
CI)
.,j.j ..
C.f.l .-
.- E
0 .....
0 '.-' ..J
0 . -
0- 0
..q-~ '-
..
~ c
0
..... U
........
.J:J '-
:::s ~
0 c..
c..
0 :::>
0 I
0
- N
o
\0 V) 'oo:;t ("r') C"l - 0 -
I
(S~TIW 'q~ ^ uOHHW 19d) gre'M lUgP!~X)V
~
2!
g, ,...
u:
as
....
as
Q
...
c
(1)
"'C
'(3
(,)
e(
,.....
o
>- f/)
"C .-
:J f/)
-- >
(fJ_
>- CO
Ci5 c
cae(
c: (fJ -
;';::;" CO
..0.- (,) '"
:J =.- >
o ~ 1;) ~
~ I-- .....
o 'od' ... /!!
>- 0') as -
.:=: 0') .... 8
Q-r-cn ~
.
.
RECOMMENDATIONS
Intersection Traffic Safety Improvements
1. Hacienda Drive and Dublin Boulevard (Collision Diagram 1)
Of the five accidents that occurred at this intersection in 1994, two involved unsafe left rums
from southbound Hacienda Drive to Dublin Boulevard and two involved vehicles travelling
westbound on Dublin Boulevard failing to stop at the STOP sign. The remaining accident
involved a rear-end collision.
Because the intersection was recently constructed, accident data was available for 1994 only.
Four of the five accidents appear to be related to the high speed limit on both of the roadways.
The posted speed limit for Hacienda Drive is 45 mph and for Dublin Boulevard it is SO mph.
The two left-rum accidents involve vehicles proceeding northbound from the freeway
interchange. Reducing the speed of these vehicles would give more time for left turning vehicles
to identify these vehicles. The sight distance of the southbound vehicles may be impaired by
the crest of the freeway overpass.
The two accidents involving westbound vehicles failing to Stop were due to unfamiliarity with
the roadway. Once the drivers became aware of the STOP sign, it was too late for them to stop
in time. An advanced W17 (pictorial "STOP ahead") sign is currently located in advance of the
intersection on the westbound approach. Two additional signs would increase driver awareness:
a W56 (pictorial two-way arrow) sign on the west side of the intersection facing westbound
traffic, and a modified W7 A (pictorial T intersection) sign in advance of the intersection on the
northbound approach.
Recommendations: Install a WS6 (pictorial two-way arrow) sign on the west' side of the
intersection facing westbound traffic and a modified W7 A (pictorial T intersection) sign in
advance of the intersection on the northbound approach.
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 7
April 19, 1995
r
I
ACC
DATE
TIME
LEGEND:
1
2
3
4
5
01-10-94
05-31-94
07-23-94
10-20-94
12-30-94
15:25 L
7:30 L
2:30(0)
20:15 (0)
16:24 L
-Z=
-0-
-0-
:()
. () .
~IKE
~
(L)
(0)
o
o
@
.
D>
~
..:
C
CO
"
l:
Q)
'0
ell
:I:
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe, Rear-End
Side Swipe, Head-On
Pedestrian, Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
CITY OF DUBLIN
LOCATION:
Hacienda Dr. and Dublin Blvd.
PERIOD COVERED:
01.01-92 to 12-13.94
DATE COMPILED: 03-14-95
< '
,
1....._
,
\ .-.
Collision Diagram OJ
157-OO1T8 - 3195. K2
II
North
~
r
I
r....
i
I .
I
,
I .
.-
f..
1
,. ,
('
i
\ I
Road Closed to
through traffic
(unpaved) If
o
r-'
Recommendation
o Install W56 sign with Type
N reflector sign below.
e Install W7 A (right) sign
::: 250 feet in advance for
Dublin Blvd.
Cost = $500
I .
"---
~ ~
Rl
If
~
..-
+
DUBLIN BLVD.
:t
f)
m
z
e
:J0-
e
;U
t.
.....
e
II
North
Not to Scale
Figure ~
R1
I
I
I
I..
City of Dublin
Intersection of Hacienda Dr. and Dublin Blvd.
15HlOl T8. 3195. VB
L-
.
.
2. Village Parkway and Lewis Avenue (Collision Diagram 2)
A total of five accidents were reported at this location in 1994. Three of these were right-angle
accidents, one was a sideswipe accident, and the other was a rear-end collision.
Three of the reported accidents involved vehicles that had just entered Village Parkway
northbound from one of the driveways to the south of the intersection. In two of these cases,
the driver left the driveway, failed to see the red light at Lewis A venue, and struck a southbound
left turning vehicle. There are actually three different driveways from which vehicles may enter
Village Parkway in this vicinity. Since all of these are within 60 feet of Lewis Avenue,
motorists exiting from these driveways may concentrate on northbound traffic (to their left) and
not realize that the signal is red.
Analysis of the accidents over the previous three years reveals a total of four accidents involving
a vehicle exiting northbound from one of the driveways on Village Parkway to the south of
Lewis Avenue. No other accident pattern is present
Recommendations: None
'I
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 10
April 19, 1995
ACC
DATE
TIME
LEGEND:
S-
-0-
-0--
: ()
~
~IKE
-0-
(L)
(0)
o
o
@
.
0>
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe, Rear-End
Side Swipe, Head-On
Pedestrian. Bicycle
Backing
Daylight
Darkness
property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
"Y\I4.
CITY OF DUBLIN
~
iii'
(Q
C'D
""C
C)
...
;II:'
~
~
Collision Diagram W
,57.OQ1T8 . 4"5 - K2
LOCATION:
Village Parkway and Lewis Ave.
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 04-12-95
..
~
North
/--,
I
!
I.. i
f'
I
I...
I;."
I
DRIVEW
r .
l
,
;
,
; :
d
Recommendation
None
L_u.'
.. I
i..._
\ '
1
, .-c'
I I
I I
I I
I I
< I I
;= I I
S;
" I I
m I
~ I
:c I I
"
is I ~ I
'< I I
I I
J ~ LEWIS AVE.
"-
~Y
/
(
I ~ I L
I I
I I DRIVEWAYS
I I
I I [ FOR
I I
I I CAR WASH
I I
I I I
I I
I I
I I
II
North
Not to Scale
Figure ~
R2
City of Dublin
Intersection of Village Parkway and Lewis Ave.
t_ c
L
1SNl01 Ta . :MIS . VB
": .....---~~..~"
.
.
3. Golden Gate Drive and Dublin Boulevard (Collision Diagram 3)
Of the seven accidents that occurred in 1994, four were rear-end collisions and one involved a
truck striking another vehicle while making an unsafe right turn. The other two accidents
involved wide-load trucks making a right turn from Dublin Boulevard onto southbound Golden
Gate Drive striking the signal head for westbound pedestrians while completing the turn.
The three-year accident analysis reveals a pattern of rear.end accidents (11 of the 21 reported
accidents) evenly distributed over three of the intersection approaches. Rear-end accidents are
not uncommon at signalized intersections and are usually attributable to driver inattention.
The location of the pedestrian heads on the southwest comer of the intersection are non-standard,
possibly contributing to the pedestrian head-related accidents. Additionally, the visibility of these
heads can be obscured by larger vehicles (including buses), which regularly stop west of the
intersection travelling both directions.
As part of the planned Dublin Boulevard widening project, the signal equipment at the third
signal will be relocated behind the sidewalks. This improvement will reduce the potential for
vehicle accidents involving the traffic signal equipment
Recommendations: Pursue the planned Dublin Boulevard widening project, including relocation
of existing signal equipment to avoid future collisions.
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 13
April 19, 1995
r~~
ACC DATE TIME
1 03-10-92 16:26 l
2 04-29-92 13:30 l
3 05-07-92 17:25 l
4 08~02-92 18:30 (l)
5 08-20-92 12:56 l
6 09-30-92 16:40 (l)
7 10-11-92 15:45 (l)
8 11-30-92 19:10 (0)
9 12-21-92 12:00 l
10 01-11-93 13:30 III ):"
11 04-20-93 11 :55 IL)
12 05-15-93 17:071L) < "
13 05-21-93 19:45 IL) c:,>
.' " 14 06-10-93 09:36 III 'c
15 01-20-94 15:36 III I;;
16 02-26-94 14:14 III
17 05-02~94 09:15 l)
18 07-25-94 15:50 L) 12;
.,.,:."
19 12-03-94 13:44 IL) <',c""""',
20 12-13-94 15:45 Il) ....,;
21 12-23-94 12:00 iL) <
>',
. :,:
c;';c>'"
':':'."":""':.c
.,:':"c'c..;.":.' .' ':.,:'.,:>"'?T.,.,'"...7.\::2..~. ,.. . '.;.;,:<.c;,;
. ...>>::'. ':: ')/'::.. ,C':c. y-',:,:,v 1'?>;~!:l~ ":c.',:: .;'..
iii......... "..........i;.;ii.i:;i.... i.:... c:,.,.:,:.:.'..< .~......,.:.::'c,::
c'> ", .' '" .'... ..i:,: :':'
,..::..... ., :',c'c .', "".." ",.. ":;"
\> ':: ,>::::c.?:,:;; . " :: "::<, {8
"., >:, .,,; ..."'c'c.'....,,.
;.:,c.c:: C"""":' .,.... ';,;
.'.{.,c' .:. ' ' ";:':"C':'.'C'
. ..'cc:cC<. ';':':'.c.,
.c:;
.::::.
>C"
;'f
;,;""i
~
.....
l~i
.
cc'
(l)
~ 1\\...
~ I",...
ca
" .,...,,',>
c:
(l)
't:J
'0
"
/ ,
. ".
'..
,":,.
,:."
Collision Diagram [1]
157-OO1T8. 3/95 - K2
"'-
LEGEND:
::.,;.:.i'....
j:
-0-
-0-
;()
~ () .
~BlKE
~
(L)
(D)
o
o
@
.
D>
"'lN4
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe, Rear-End
Side Swipe, Head-On
Pedestnan, Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
. Dublin Blvd.
'!~:';111:9~'I~.:';;i..i...
dia...... Si,,:.i:;..{';;' ..!i; ......,..... ..'r.
;." ..,.....,:"/"',, ,; ,..,c,c.., ::. . "d, ,'. 'i
'; ""':,:"",, ". .'. " .."."",., .""",;.,,.. ".",', , ..,,:::;::c'
'c':,
'.:,::
,.,.,:,;::.;;.,
"Y
CITY OF DUBLIN
LOCATION:
Golden Gate Dr. and Dublin Blvd.
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 02-14-95
~
~
North
"."!
...,
-
, .'
L _
r--
t.
.
\,
~ t t
r ,..,
Bus Stop
r-
I,D
- I,.
-----------
-------_........--~-_.
......
...4--
~
,------------
DUBLIN BLVD.
,
, '
\
------------
,-
i
I
l.,
1,6
1'6
--~~_...........-----~----
Bus Stop
r-
/
o
Recommendation
Relocate signal poles
behind sidewalk as part of
the planned Dublin Blvd.
widening project.
~
Cost::;:: Not available
(j)
o
6
m
z
(j)
~
m
o
;0
\.,-.'
L
g
North
Not to Scale
FIgure ~
R3
" J
'--
I
\ '
L_'
I
I
L.
City of Dublin
Intersection of Dublin Blvd. and Golden Gate Dr.
157-001 Te. 3I1l5 . VB
.
.
.'-
4. Dougherty Road and Sierra Lane (Collision Diagram 4)
This intersection currently operates with STOP-sign control on the Sierra Lane approaches. Of
the four accidents reported at this intersection in 1994, one involved an out-of-control vehicle
striking a parked car, one involved a rear-end collision, one involved a eastbound vehicle turning
left from Sierra Lane striking a vehicle travelling northbound on Dougherty Road, and one was
an injury accident with a vehicle striking a pedestrian.
Analysis of all of the accidents at this intersection over the past three years reveals no discernible
accident pattern. The City is planning to signalize the intersection; this improvement will reduce
the potential for right-angle accidents.
Recommendations: Pursue the planned installation of a traffic signal at the intersection.
:..
~ 994 Traffic Safety Study
T JKM Transportation Consultants
Page 16
April 19, 1995
.
ACC
DATE
TIME
LEGEND:
j:
-0-
-0-
~()
~
~BlKE
~
(L)
(0)
o
o
@
.
0>
~
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe, Rear-End
Side Swipe. Head-On
Pedestrian. Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
CITY OF DUBLIN
LOCATION:
Dougherty Road and
Sierra Lane
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 02-21-95
Collision Diagram m
157-OO1T8. 31$5. K2
..
~
North
r-',
('
i ,
\
,~. .,
I~I
\ I I
i I~I
'.- I I
r ., I I
I
i I
I
,- I
I
I
SIERRA LN.
114'
~
R1 ~
~
r-
Recommendation
o Install traffic signal
control as planned by
city.
g 6'
e> *
:I:
m
::a
:;!
::a
!=l
Cost:;:; Not Available
Note:
Heavy Reconstruction at many
Points In Intersection.
\ ,
i .
i......
* Median Is recently constructed
!
L.-
r
I
l~
City of Dublin
Intersection of Dougherty Road and Sierra Lane
157-001 T8. 3195. VB
..
North
Nollo Scale
Figure
~
R4
-,"'-~.--
.
.
5. San Ramon Road and Silvergate Drive (Collision Diagram 5)
Of the four accidents that occurred at this intersection in 1994, two were rear-end accidents. one
involved a vehicle striking the pedestrian island at the northwest comer of the intersection. and
one was a rut-and-run accident with a vehicle failing to stop at the signal.
The accident history of the past three years reveals no discernible accident pattern.
Recommendations: None
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 19
April 19, 1995
I,
I
ACC DATE TIME LEGEND:
1 06-24-92 ~ Right Angle
r . 2 03-14-93
3 03- 14-93 Left Turn
4 05-24-93 -0- Rear-End
5 06-23-93
6 02-25-94 -0- Head-On
7 09-16-94 ~() Side Swipe, Rear-End
8 09-17-94 . () . Side Swipe, Head-On
9 , 0-24-94
r~' ~B1KE Pedestrian, Bicycle
'I' ~ Backing
(L) Daylight
r " (0) Darkness
l 0 Property Damage
0 Fixed Object
, ~ Injury
. Fatal
0> Parked Car
~ Out of Control
r-
\
,
e ,
" .
L
\ '
\......
\
L.-
Collision Diagram rn
I
l., 157-OO1T8. 3115. K2
CITY OF DUBLIN
LOCATION:
SlIvergate Dr. and San Ramon Rd.
PERIOD COVERED:
01.()1-92 to 12-13-94
DATE COMPILED: 02-21-95
!!~
r-,
I
r
\
'.
f
i
,
,~
\
I
I .,
r'
I
I
\
i.o_
, ""'I ~
i . z
I ::0
>
i:
0
Z
"
!='
SILVERGATE DR.
t :
I .
{i
..-
r
I.;,
!
i
,
Recommendation
None
I ~: .
'--
L
i
L...
-..
~ t: t
I
I
I
I
I
I
I
I
I
Figure
City of Dublin
Intersection of San Ramon Rd. and silvergate Dr.
{
L.
157-001 T8. 3195 . VB
R5
Ii
North
Not to Scale
~
.-.~..-
.
.
6. Regional Street and Dublin Boulevard (Collision Diagram 6)
Of the 11 accidents that occurred at this intersection in 1994, 5 were rear-end collisions,
3 involved left-turning vehicles, 2 were sideswipe accidents, and 1 was a right-angle collisioIl
Due to redevelopment of the southeast quadrant of the intersection during 1994, traffic volumes
have steadily increased. The intersection is currently operated by a five-phase signal with
permitted left turns on the northbound and southbound approaches. Between 1992 and 1994,
five accidents involving northbound left turning vehicles striking southbound through vehicles
were reported. This type of accident could be virtually eliminated through modifications to
provide exclusive left-turn phasing on the northbound and southbound approaches. The existing
traffic signal will be modified to provide eight phases in conjunction with the planned Dublin
Boulevard widening. This improvement will reduce the potential for right. angle accidents
involving the northbound and southbound approaches.
Recommendations: Pursue the planned widening of Dublin Boulevard, including the
modification of the existing traffic signal to provide eight-phase operation.
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 22
April 19, 1995
ACC DATE TIME
1 01-28-92 LEGEND:
2 02-20-92
3 04-25-92 S- Right Angle
4 04-26-92 Left Turn
5 05-07.92
6 07-10-92 -0- Rear-End
7 08-28-92 ~ Head-On
8 09-07-92 : () Side Swipe, Rear-End
9 10-07-92
10 10-14-92 . () . Side Swipe, Head-On
11 10-20-92 ~KE Pedestrian, Bicycle
12 11-25-92
13 05-01-93 ~ Backing
14 06-29-93 (L) Daylight
15 10-14-93 (0) Darkness
16 04-24-93
17 12-15-93 0 Property Damage
18 02-16-94 0 Fixed Object
19 02-24-94 @ Injury
20 03-01-94
21 03-04-94 . Fatal
22 03-10-94 0> Parked Car
23 03-12-94
24 04-04-94 1M- Out of Control
25 07-17-94
26 11-04-94
27 11-18-94
28 11-21-94
CITY OF DUBLIN
LOCATION:
Regional St. and Dublin Blvd.
PERIOD COVERED:
01.01-92 to 12-13-94
DATE COMPILED: 02.21-95
Collision Diagram rn
!!~
'.,
L
lSNlO1TB . 3IllS - K2
r
f-
I
\
,"
r-.
,
i
I.
r
L-
r. \
i
I.
~ l ~
{--.
.'
------------
~
--------------
------------
...-
--------------
~
o
...-
....f'
....
-------------
1_:"
...
--------------
DUBLIN BLVD.
f'
; ~ ,
......
f-
i
Recommendation
o Modify signal to provide
eight-phase operation in
conjunction with planned
Dublin Blvd. widening.
~ ~
"
m
a
(5
z
)00
r-
en
:-I
Cost;;: Not available
L
r
L
City of Dublin
Intersection of Regional street and Dublin Blvd.
II
North
Not to Scale
Figure ~
R6
L
\ !
L,.,
157-001 T8. 3195 . VB
-,...~....-'
.
.
7. Stagecoach Road and Amador Valley Boulevard (Collision Diagram 7)
There were four reported accidents at this location in 1994. One involved an unsafe turning
movement, one involved very excessive speed, one was a rear-end collision and the other
involved a pedestrian being struck.
Analysis of all of the accidents during the previous three years reveals no discernible accident
pattern.
Recommendations: None
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 25
April 19, 1995
r-
ACC DATE TIME
1 05- 19-92 12:44 L
2 11-10-93 17:15 D
3 01-19-94 18:10 (D)
4 02- 17-94 06:50 (D)
5 09- 1 9-94 08:30 (L)
6 1'-'0-94 08:25 L)
.---
it..
, "
I .-.
..;
'--
: ;
1...-
l........
LEGEND:
-t=
-0-
-0-
~()
~ () .
~B1KE
~
(L)
(D)
o
o
@
.
0>
1,IIA.....
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe. Rear-End
Side Swipe. Head-On
Pedestrian, Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
CITY OF DUBLIN
LOCATION:
Amador Valley Blvd. and
Stagecoach Rd.
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 04-12-95
Collision Diagram W
157-l101T8 - 4115 - K2
II
~
North
r-
\ '
\
r.o.
[
r"
; ,
i_....:'
I'
I
,
i
1 ~
! t. ,',
~
~ .;1
(c
I
t
Recommendation
None.
L
i "
L
,
~
AMADOR VALLEY BLVD.
-----------
...-..-
.-
~
C)
m
o
~
o
::J:
::D
!='
i "
L."
City of Dublin
Intersection of Stagecoach Rd. and Amador Valley Blvd.
(
i..-
157-001 18 . 3195 . VB
II
North
Not to Scale
Figure ~
R7
-~,....-_.
.
.
8. Donohue Drive and Amador Valley Boulevard (Collision Diagram 8)
Five accidents were reported at this location in 1994. Three of these were rear-end collisions
and the other two involved bicyclists.
Analysis of all of the accidents at this location over the previous three years reveals no
significant accident pattern.
Recommendations: None
1994 Traffic Safety Study
TJKM Transportation Consultants
Page 28
April 19, 1995
r
ACC
DATE
TIME
LEGEND:
S-
-0-
-0-
;-0-
4(}
~B1KE
~
(L)
(0)
o
o
@
.
[J>
"VV4.
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe. Rear-End
Side Swipe, Head-On
Pedestrian, Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
CITY OF DUBLIN
LOCATION:
Amador Valley Blvd. & Donohue Dr.
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 04-12-95
\._~
Collision Diagra~ [i]
157-OO1T8 . 41t5 - K2
.....-.
..
~
North
r
c'
r
,
I
r:,
,
i,
r
'- ;
{"'
i
I ;
r-"'l
-----
--
--
-4'-
, ,
! '
. ,
r
i '
t~;
/'
/'
--
--------~
--
!-~,
Recommendation
None.
I
I ,
----
i.'
L
AMADOR VALLEY BLVD.
.-
c
o
z
o
:l:
c:
m
c
;z:l
i '
l,~
City of Dublin
Intersection of Donohue Dr. and Amador Valley Blvd.
(
(,
L
157-{)()1 T8.:Ml5. VB
II
North
Not to Scale
Figure ~
R8
.
.
9. Village Parkway and Brighton Drive (Collision Diagram 9)
Four accidents were reported at this location in 1994. Two of these were caused by vehicles
failing to stop at the STOP-sign. One of these was a right-angle collision and the other involved
a vehicle striking a fixed object. The other two accidents at this location were rear-end
collisions.
Analysis of all of the accidents over the previous three years reveals a total offour accidents
caused by vehicles failing to stop at the STOP sign. It should be noted that the City of
Dublin is planning to eventually install a traffic signal at this intersection, This improvement
should reduce the potential of accidents of this type.
Recommendations: None
~ 994 Traffic Safety Study
T JKM Transportation Consuffants
Page 31
April 19, 1995
r-
ACC DATE TIME
1 09-14-92 15:10 L LEGEND:
2 06-16-93 12:40 L
3 10-05-93 06:35 0 -I; Right Angle
4 02-09-94 08:00 (L Left Turn
5 06-2()"94 21:40 (0)
6 09-09-94 08:30 (L) -0- Rear-End
7 11-03-94 22:00 (0) -0- Head-On
'-_J ~ () Side Swipe, Rear-End
. () . Side Swipe, Head-On
.., ~BlI<E Pedestrian, Bicycle
~ Backing
{L} Daylight
{D} Darkness
0 Property Damage
0 Fixed Object
@ Injury
. Fatal
D> Parked Car
~ Out of Control
'--
CITY OF DUBLIN
LOCATION:
village Parkway and Brighton Dr.
PERIOD COVERED:
01..Q1-92 to 12-13-94
DATE COMPILED: 04-12-95
Collision Diagram [I]
51
~
North
157 -001T8 - 4/95 - 1<2
.
.
, .
r
r
\
\
r.
r-'
I I I
I I
I I
I I
s; I I
r- I I
>
G) I I
m
~ I I
::tJ I I
~ I ~ I
I I
R1T I (II R1 I
) \ It R1 BRIGHTON DR.
R1" '\
I R1 i ~ ..L
I R10
I
I
Recommendation I
o Trim bushes to improve I
I
visibility of STOP sign I
on southeast corner. I
I
I
I
,-
l'
1_
r""
.I '
\- :
r', ,
\ ;
,
'- '
r....
,
;
,
, ,
r.
t .
i... ,i
I
i
\
L
L
f__
L
City of Dublin
Intersection of Village Parkway and Brighton Dr.
II
North
Not to Scale
Figure ~
R9
157-001 T8. 3/95 . VB
o.,~_:...;.'-""
.
.
Roadway Segment Traffic Safety Improvements
1. Regional Street between Dublin Boulevard and Amador Valley Blvd. (Collision Diagram 10)
Of the three accidents that occurred on this facility in 1994, two involved vehicles turning left
into driveways and one involved a loose animal in the roadway.
Analysis of all of the accidents during the previous three years reveals no discernible accident
patterns.
Recommendations: None
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 34
April 19, 1995
I
ACC DATE TIME LEGEND:
1 12-31-92 -Z= Right Angle
r' 2 01-05-93
3 02-17-93 Left Turn
4 08-18-93 -0- Rear-End
5 02-22-94
r 6 05-31-94 -0- Head-On
r 7 12-16-94 : () Side Swipe I Rear-End
.... .. () . Side Swipe I Head-On
r.... ~BlKE Pedestrian. Bicycle
i ~ Backing
-- .
(L) Daylight
,r - ~ (0) Darkness
0 Property Damage
0 Fixed Object
@ Injury
. Fatal
0> Parked Car
~ Out of Control
.-.
, .
: .
'--
, ,
I
\.....-'
Collision Diagram 1101
(
I
L 151.Q01T8 - 3IV5. K2
CITY OF DUBLIN
LOCATION:
Regional Street between
Amador Valley and DUblin Blvd.
PERIOD COVERED:
01~1.92 to 12.13-94
DATE COMPILED: 02-22.95
!!~
-~_...
.
.
2. Amador Plaza Road between Amador Valley Boulevard and Dublin Boulevard (Collision
Diagram II)
All three of the accidents that occurred on this facility in 1994 involved WlSafe turning
movements. There was no discernible pattern to these accidents. Amador Plaza is fronted by
many driveways. A two-way left-turn lane (TWLTL) is provided for movements from these
driveways.
Analysis of all of the accidents during the previous three years reveals no discernible accident
patterns.
Recommendations: None
~994 Traffic Safety Study
T JKM Transportation Consultants
Page 36
April 19, 1995
ACC DATE TIME LEGEND:
1 05-14-93 S- Right Angle
2 05-27-93
3 01.13-94 Left Turn
4 11-19-94 -0- Rear-End
5 12-10-94
-0- Head-On
~ () Side Swipe, Rear-End
4 () . Side Swipe, Head-On
f~ ~KE Pedestrian, Bicycle
-0- Backing
(L) Daylight
r' \ (0) Darkness
0 Property Damage
0 Fixed Object
@ Injury
. Fatal
0> Parked Car
~ Out of Control
;~
, ,
L.
Collision Diagram 11'11
157-OO1T8.31t5 - K2
CITY OF DUBLIN
LOCATION:
Amador Plaza Rd. between
Amador Valley Blvd. and Dublin Blvd.
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 02-22-95
~~
North ~ ~
,..~_..-'-'
.
.
3. Sierra Court between Trinity Court and Sierra Lane (Collision Diagram 12)
Of the three accidents that occurred on this facility in 1994, two involved unsafe backing and
one involved an illegal turning movement.
Analysis of all of the accidents during the previous three years reveals no discernible accident
patterns.
Recommendations: None
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 38
April 19, 1995
I
r
I
r-
I ACC DATE
1 TIME LEGEND:
1 09-24-92 j: Right Angle
2 1 ().(l8--92
3 12-23-92 Left Turn
4 05-25-93 -0- Rear-End
5 07-21-93
r. 6 09-09-93 -0- Head-On
, 7 06-23-94 : () Side Swipe, Rear-End
L.
8 07.14-94 . () . Side Swipe, Head-On
9 08.23-94
r, ~BlKE Pedestrian, Bicycle
! ~ Backing
"..
(L) Daylight
",'. (0) Darkness
\
0 Property Damage
0 Fixed Object
,....'.-
~ Injury
. Fatal
0> Parked Car
4'Vl-.. Out of Control
: '
,
"
;
\ ,
t:
:::I
o
U
cu
...
...
.2!
en
I'-
1L
L
i ,I
I
L
r
\
'-'
Collision Diagram 1121
I
t. .
L 157.00118.3/95. K2
CITY OF DUBLIN
LOCATION:
Sierra Court between
Trinity Court and Sierra Lane
PERIOD COVERED:
01-01-92 to 12-13-94
DATE COMPILED: 02-22-95
II
North
~
.
.
4. Amador Valley Boulevard between Village Parkway and York Drive (Collision Diagram 13)
There were a total of three reported accidents at this location in 1994. Two of these involved
bicyclists riding on the wrong side of the road and colliding with vehicles exiting from
driveways. The other accident involved an intoxicated driver striking a fixed object.
Analysis of all of the accidents during the previous three years reveals no discernible accident
patterns.
Recommendations: None
'994 Traffic Safety Study
T JKM Transportation Consultants
Page 40
April 19, 1995
r--
'.,-'
LEGEND:
r" ACC DATE TIME
: 1 09-21-92 j: Right Angle
L ~. Left Turn
2 09-29-92
3 03-27~93 -0- Rear-End
r-'"'
4 09--3(}.94 Head-On
5 1 (}.25-94 -0-
6 11-02-94 : () Side Swipe, Rear-End
.:...n... Side Swipe, Head-On
~IKE Pedestrian, Bicycle
-0<<+ Backing
(L) Daylight
(D) Darkness
0 Property Damage
0 Fixed Object
Ci9 Injury
. Fatal
D> Parked Car
1/11I.+ Out of Control
r
I
.-
; .
i .~,-
'--
,
I
L,.
,
I
Ld
Collision Diagram 1131
i 157.00118 . 3Ill5 . K2
L
CITY OF DUBLIN
LOCATION:
Amador Valley Blvd. between
Village Parkway and York Dr.
PERIOD COVERED:
01..()1-92 to 12-13-94
DATE COMPILED: 04-12-95
~
~
North
._~>'
.
.
S. Dublin Boulevard between Village Parkway and Clark Avenue (Collision Diagram 14)
There were a total of six accidents reported at this location in 1994. Five of these were right-
angle accidents and the other was a rear-end collision.
Three of the accidents at this location involved vehicles turning left from eastbound Dublin
Boulevard into the BIG-O tire store. Another involved a similar left turn from eastbound Dublin
Boulevard into an unspecified driveway.
The City Police Department has indicated that some accidents on this segment have involved
eastbound vehicles making V-turns in the vicinity of Village Parkway. The Police Department
has recommended that "NO U.TURN" signs be installed for eastbound traffic. Although
motorists should be aware that V-turns are illegal in a business district. it appears that additional
signing in this area would be an appropriate reinforcement of that fact.
Recommendations: Install "NO U-TURN" signs for eastbound traffic on Dublin Boulevard
approximately 2S0 feet east of Village Parkway.
1994 Traffic Safety Study
TJKM Transportation Consultants
Page 42
April 19, 1995
r
I
I
/.\
ACC DATE TIME
1 03-30-92 08:55 L
2 11-30-92 16:15 L
3 01-25-93 14: 11 L
4 12-16-93 11 :58 L
5 04..07-94 13:20 L
6 06-20-94 11:45 L
7 08-25-94 16:40 (L
8 11-11-94 12:18 (L)
9 11-22-94 13:00 (L)
10 11-25-94 13:55 L
LEGEND:
1=
-0-
-0-
: ()
. () .
~BlKE
~
(L)
(0)
o
o
3
.
0>
~
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe, Rear-End
Side Swipe, Head-On
Pedestrian, Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
CITY OF DUBLIN
,---,
I. .
Collision Diagra~ 1141
157-OO1T8 - 3195. K2
'.......
LOCATION:
DUblin Blvd. between
Village Parkway and Clark Ave.
PERIOD COVERED:
01-01-92 to 12.13-94
DATE COMPILED: 04-12-95
~
North
~
.
.
6. Dublin Boulevard between Golden Gale Drive and Amador Plaza Road (Collision Diagram 15)
A total of four accidents were reported at this location in 1994. Two were rear-end collisions.
one was a bicycle accident and the other was caused by an WlSafe lane change.
Analysis of all of the accidents over the previous three years reveals that five of the eight
accidents within this roadway segment were rear-end collisions. This type of accident is not
uncommon on segments with significant queues and a large number of driveways.
It should be noted that this segment of Dublin Boulevard is planned to be widened to six lanes
as part of the upcoming widening project The effect this widening will have on the accidents
on this segment is unknown.
Recommendations: None
1994 Traffic Safety Study
T JKM Transportation Consultants
Page 44
April 19, 1995
. I-
i
.
ACC DATE TIME
1 09-30-92
2 10-11-92
3 12-24-92
4 08- 14-93
5 06-01-93
6 07-23-94
7 08-27-94
8 10-07-94
lEGEND:
S-
-0-
-0-
:()
'()
~B1~E
~
(L)
(0)
o
D
~
.
0>
~
Right Angle
Left Turn
Rear-End
Head-On
Side Swipe, Rear-End
Side Swipe, Head-On
Pedestrian, Bicycle
Backing
Daylight
Darkness
Property Damage
Fixed Object
Injury
Fatal
Parked Car
Out of Control
CITY OF DUBLIN
Collision Diagram 115\
157-OO1T8 .3/95 - K2
LOCATION:
Dublin Blvd. between
Golden Gate Dr. and
Amador Plaza Rd.
PERIOD COVERED:
01..Q1-92 to 12-13-94
DATE COMPILED: 04-12-95
~
North
~
I
i
.
.
r-
!
APPENDIX A
Results of the Analysis for Statistical Significance
;,--
,
I
L_
Cil:s:
> 0
0-
.oC])
<tCD
'-'0
C]) '-
:s:E
00
~-lC,)
0>
0> _
T"'"'-O
C]) '-
0.-
0.1::
::J8
.
w w
> >
g g
<( <(
(")1"-..... CXlI"-"<I' (")C\ll"-
'<to.....~I"-OCXlC\l(")
a;c?~~99999
(l)C\l<'o
..... C\l (0
999
(")1"-"'" CXlI"-"<I' "<I'C\lI"-(l)C\l(O
~(l)OC\l<'o(l)I"-.....C\lOr:1f)
.....uiui~MNMMMM(")M
.....
000 CXl(O(l)If)OCXl CXlO(l)
. ..... 0 0 0 CXl <.0 I"- I"- If) If) "<I' U1 U1
O~OOONNOMOMOO"'"
Oct$
<ta:
'0$
'- C
Q)C])M
.0'00>
E '0 .
::J U
z<t('IJ
sn
'---
I
\~
OOOC\l(")C\l"<l'.....<.O..........C\l
~
sn
000 o "<1'<.0 C\llf) C\l (")0.....
O.....O.....If)C\lC\lC\lC\lIf)(")(")
(01"-.....C\lC\l"<l'''<I'CXl.....cn''<l'C\1
I-If)"<I'OO(l)(l)C\lIf)(l)If)(l)"<I'
~.....I"-C'I.l..cnOCXl(l)"<I'Ln<.O"<I'''<I'
..::; ..... ..... M <J:i N u"i -.i Ln' u"i M
>
0000000"<1'0000
LnIf)LnLnLnOOC\lIf)OIf)Ln
I- (0 ..... I"- Ln <.0 0 I"- Ln <.0 (l) I"- "<1'_
O":-.ia:iNNa:i-.i-.iM-.iN(")
<( .....(")C\lC\lC\lC\lC\lC\lC\l
.c 0
'5>-;g
a5E
-l
o If) 000 If)LnLl) 0 Ll)Ln
LnC\lOOOC\lI"-C\lOI"-I"-
(l) I"- CXl If) (").(0..... O.C'I.l..C\l1"-
..... .,... T""'" .... T"""'
-ci
a: :>.
ell
-ci...;....:~~
a:OOOa::a.
o c5~g~~o&lli ~
a: c> E.2c:l"Og;:
al;> ell Ole ~>..... c:...;~
~Ci~ga:~~<(~~...JOal
Wal~'E~oog-ciG~&~
.....JiiiCl.....o8oo~c:l....:a:.....o$.g i5
::J o.........oOell 0000
O .....0 .... a: .
_~c5 >-c '2~>-ooo
C!l "':elloCi.i,~a::]-:""''''''
zi:7.i.!03E(ij'-'...a.~c:d
~oellC:c:ellC:C:Oal<(...J
(0- ~~.Qa:.2~-g Cl.c ~~
5~~~8~is~~c3058
.
Cil:s:
>0
0-
.oC])
<tCD
meC;;ffi~friM~
~c.999999
00
.;t-lU
0>
Ol _Lnl.'\lLnI"-..........
T"'"a;e(")<.O-.::t:U1-.::t:-.::t:
0....,........,.-..........................
o.C
::J8
(l)0"<l' 00 C\l
. Q)WO'<t0 "<I'C\j
o.....ddddd.....
urn
<ta:
C\lO.....O.....(")
'<t
O'l
'O(/)-
....E
Q)Q)(")
.o"Om
E '0 .
::J 0
z<tC\J
9'l
.,...QT"""T"""'M"'-
NO...............M.........
Ln"<l'''<I'''<I'LnCXl
I-m!;;:::e~;:;;;!:
::Er-:"';<J:i-.i<J:ilIi
>
000000
I-~ggg~g
Oaiwwo"':o
<(...............C\lC\lLn
.c.
-,.-
0) .
c:E
~
000000
01f)1f)000
.....C\ll"-(")(")I"-
N~"":~"':
CD
>-
Ci:mai<D
....:lli<D~,gg
OO~Cii....oell
ClO::J,C
<t g C:o Q;> 'E Cl ~
OEc W <D
a:g~U)~BE
..cooaio
5BOO:ri:~~
~-gg~O~B
<ta: ai c5 c: ~ :: al '
ell 0 0 ... 0
Zin ell c: ~"O.5,
......RE~alell:O'
;n<gt5~~a'
r--
i
r
J-
'Q;;:
> 0
0-
.cO>
<(m
"-0
0>"-
;:E
00
'<t..JO
m
m _
......"-0
0>"-
0.-
o.C:
::>8
r-.
,
i
......<D'<t0<Da::>
C\I'<tMC\lU')M
999099
~j:!~g:~~
LriLriLriLriLriLri
MO......a::>M:::;:
. 0> a::> O'! U') "": 0 "
8roc::i......M........tLri
<(0::
-(f)
0_
c:
0:;0>('1)
.cum
E'U.
::J U
z<(C\J
9>
L..
.!::
&--:
~:E
..J
......C\I'<tC\l'<t<D
"""
9>
......0 0 C\lMU')
OO......MN'<t
'<ta::>CllC\l............
I-~~::~~~
:::2MNM-.iNM
>
000000
I-~~~~gg
OONN";cDcD
<(~""~""-T"""T"""
000000
OU')U')OLOU')
....... ~ "'. t-: a::> Cll
~ T""" ~..,.....
05
~CIl
";[ij~
.....,,;0> III
>-oo..!<:.....'~
~<(::g.:::~.gjCi5
o 0 (ij cd
>EEES.6
o:~.Qlco<J::_:C
.......~ccl-oa:l::J
.....0 0->-0
o..-:s-cCllO
w~.....c 'iij-:
~<o ~>~
:5[ijcog~:S<J::
':::-CO'01Il
,.I:lEo,cEcd-
..... ~.g'_E:i=
>S2oco':::<J::.3
.
'Q;;:
> 0
0-
.cO>
<(m
w
>
o
co
<t:
"-oreg:~~~m~
;E~99'7999
00
"""..Jo
m
m -:;<Da::>CllCllCOCllM
"'-"-OQ)<DdlCO..,.'<tN
~'=MC\iC\iMMMM
o.C:
=>8
~!:::M~~gg
s!C\ic::iC\i..tc:ic:ic::i
<(0::
- (f)
0_
c:
0:;0>('1)
.cum
E'- .
::J 8
z<(C\J
9>
C\lC\I'<tM"-OO
o:::t
9>
NLt)r-.......N.,....,.....
O'<tC\lC\lNOC\l
Mcoo......mCOa::>
1-~~~8~~;1;
:::2N"":-.iNNNM
>
0000000
I-g~g~~~R
Oooci~aiaici
<(C\lC\lN...... ......
.!::
&--:
~:E
..J
0000000
U')OOOIJ)LOO
IJ) Q). C\I. en ~ IJ). ~
........... ".................
>.
~~ ~
ciU5~a. ,~
>ltico~ 'O(])
ffigO:::Jg,,; a:-€
>-'~:S>c 13s
wa:~S~";8Cl
::loE-ci>-ClCllS
<(;j<J::a:s~g-o
>a:~~>.~u;a:
O::':::u;..!2~oo-5
OEo_a.~--:co
cd.....a.,,;.....O
o cd.::: 0 CIlCCO
<(a:.2'00l..!<:':::~
:::2 .::: OJ co co 0;; .::: ~
.....co(])E=oCll~
.....cnO:<J::>>-a.C/)
.
Q);:
> 0
0-
.cO>
<(m
"-'0
0>"-
;:E
o 0
.q-...Jo
m
m _
......"-0
0>"-
0.-
o.C:
=>8
OI.OMa::>O"-
......LOC\lN~..-
9999'79
Mm<DC\I'<t'<t
......0'!CC!......'<t1J)
C\i...............-N-r-
MmNNr--m
.001'-:U')M......~m
8moc::ic:io......c::i
<(0:
o:::t
9'l
-(f)
0-
"- c:
0>0>('1)
.cum
E'u.
::l U
z<(C\J
9>
T"""T"'""..........C\I.......'IIIi;f
OOOMON
ONO'<tNN
......MN..-......N
I- Ie ::g ~ t;:; ~. ~
~M.,fCO,...:N::
000000
1-~~5':5':5':5':
Oocir-:criNM
<(~T"""T""".....-N~
.!::
-.--
0> .
~:E
...J
-0
0:
~
(])
W
o
o ~
<(g
~~
r:.9
0:-0
wa:
I~
~ ~
=>0
O[ij
Ou.
000000
I.OOU')I.OOU')
a::>MIJ)O<D~
"":NNN ......
CD
>- .
Jgc
III :>.
> ~
o - Q
'02c: .:::
~5...J ~
<t: :E ~ Ci5 ~
_o.9<D .$
-' U5 ,5: E
-ciCDo:go
~ ~:o:.g
3l~O.8.8
o>~':::Ci5
~ .g ~ -; ,6
ocoEc.o-
=Eow
~<~U50
. ~ Transpo....on ConSUltants.
.
"''''/~
ncCEtVtD
MEMO
;'p ^ r., : .t
.d~'\ t II 10('\-
" .:..,~..r i.,.; ":.....
March 10, 1995
p; · :'"'' I , ....... ~ ~ t ,_~... "
, ..J !:) ,,_ J l, "'/1 ) '_' ,,' ,-'
Project No.:-157~1 Task 9
To:
Mr. Mehran Sepehri
From:
Carl D. Springer and Ouistopher S. Kinzel
Subject:
Downtown Dublin Traffic Monitoring
Background
The traffic counts for the annual Downtown Dublin traffic monitoring program have been
completed. The program is part of the Downtown Specific Plan adopted in July 1987. The
monitoring program consists of traffic counts taken annually at key intersections within and
leading to the Downtown area.
Five intersections have been monitored annually since 1987. Turning movement counts were
conducted in February 1995 (used for 1994 analysis), during the p.m. peak hour at the
following intersections:
· San Ramon Road! Amador Valley Boulevard
. Dublin Boulevard/Regional Street
· San Ramon Road/Dublin Boulevard
· Dublin BoulevardNillage Parkway
· Dublin BoulevardlDougherty Road
San Ramon Road and Dougherty Road are major commuter routes providing important north.
south mobility between San Ramon and Pleasanton. These roads provide access to the heart
of Dublin via Dublin Boulevard and Amador Valley Boulevard.
The intersections of San Ramon Road/Dublin Boulevard and Dougherty Road/Dublin
Boulevard serve as gateways to the City, but their operation is very much affected by through
traffic with origins and destinations outside of Dublin.
Analysis
Table I indicates the total volume entering each intersection from 1989 through 1994. These
data are displayed graphically in Figure 1. For each intersection, the growth rate was
calculated between 1993 and 1994, and between the five-year average from 1989-1993 and
1994. The latter rate reduces the effect of yearly fluctuations.
4637 Chabot Drive, Suite 214, PleasaDtoD, CA 94S88.27S~
P.....nton . Fresno . Santa RON
EXHIBIT .~- -
Doun\--Iwrr\ \ n'tUsetticrY\ Hc-n.i ~
~eflOY-c fwv' T...j K...t-1
'Mr. Mehran Sepehri
.
Page 2
.
March 10, 1995
Table I:
Growth Rate
(percent)
Vs. Vs.5
Intersection 1989 1990 1991 1992 1993 1994 1993 Yr. Avg.
1989.93
San Ramon Rd.! 3,389 3.320 3.300 3,396 3,486 3,774 +8.3% + 11.7%
Amador Valley Blvd,
Dublin Blvd.1 3,285 3,630 2,995 3,353 3,034 3,370 +11.1% +3.4%
Regional St
San Ramon Rd.! 5,945 5,465 5.890 6,560 5,750 5,903 +2.7% -0.3%
Dublin Blvd.
Dublin Blvd.! 3,259 2,926 2,757 3,122 2,973 3,089 +3.9% +2.7%
Village Pkwy.
Dublin Blvd.! 4.054 4.360 4,475 4,082 4,419 4,680 +5.9% +9.3%
Dougherty Rd.
TOTAL 19,932 19,701 19,417 20,513 19,662 20,816 +5.9% +4.9%
Comparison of Total Intersection Peak Hour Traffic
While all of the five intersections studied show traffic growth over last year, only two
intersections, San Ramon Road/Amador Valley Boulevard and Dublin Boulevard/DOugherty
Road, show significant traffic growth when compared to the previous five-year average. For
San Ramon Road/Amador Valley Boulevard, two movements contributed to the majority of
the growth in traffic at this intersection. The northbound through movement increased 26.4%
(from 826 to 1,044 vehicles per hour) over 1993 traffic counts, while the westbound right turn
movement increased 35.9% (from 426 to 579 vph) over the same period. For Dublin
Boulevard/Dougherty Road, the eastbound through movement contributed to the majority of
the increase in traffic at the intersection, with an increase in traffic of 136% (from 130 to 307
vph) over 1993 traffic counts.
Volume~to-capacity (V/C) ratios were calculated for each of the five intersections to determine
the levels of service (LOS) during the p.m. peak hour. Table IT shows a comparison of the
levels of service for 1990, 1991, 1992, 1993 and 1994. (Detailed calculations are attached.)
As the table indicates, for three of the five intersections studied, the V /e ratio increased when
compared to 1993 values. These increases are explained by the increased traffic volume at
these intersections. At the other two intersections the V /C ratio actually dropped while the
traffic volumes slightly increased. This is explained by a decrease in traffic volumes at
certain critical movements within the intersection.
'Mr. Mehran Sepehri
.
Page 3
.
March 10, 1995
Table U:
Intersection Levels of Service
1990 1991 1992 1993 1994
Intersection vie LOS vie LOS vie LOS vie LOS vie LOS
San Ramon Rd.! 0.66 B 0.65 B 0.66 B 0.68 B 0.72 e
Amador Valley Blvd.
Dublin Blvd.! 0.85 D 0,65 B 0.73 e 0.67 B 0.70 B
Regional St
San Ramon Rd.! 0.89 D 0.89 D 0.92 E 0.86 D 0.85 D
Dublin Blvd,
Dublin Blvd.! 0.67 B 0.62 B 0.71 e 0.67 B 0.65 B
Village Pkwy,
Dublin Blvd.! 0.85 D 0.87 D 0.79 e 0.77 C 0.86 D
Dougherty Rd.
Notes: V/C "" Volume-to-Capacity Ratio
LOS "" Level of Service
Conclusions
The increase in traffic at San Ramon Road! Amador Valley Boulevard indicates an increase in
p.m. peak hour destinations north of the intersection. However, the increase has been
observed only over the past year and is possibly attributable to statistical fluctuations. The
increase in traffic at Dublin Boulevard/DOugherty Road is most likely attributable to the
recent Dublin Boulevard eastward extension. As noted, the eastbound through movement
traffic has increased 136% over 1993 traffic. Based on a comparison with the previous five-
year average, the other three study intersections do not appear to have statistically significant
increased traffic volumes.
All five intersections studied are currently operating at acceptable levels of service based on
the City of Dublin's LOS standard of acceptability. Therefore, no level of service
improvements are recommended for any of the study intersections.
P.
A""-'
m.oolL1YB
~~ ~~~~ ~~~ ~~~ ~~~
@ ~i;;;; ;;;.;;; ;;; i ·
I ~~I~~~~ ~~~ ~~~ ~~~ i~!~ ~i
~ ; ~-~~~~ ~~
~ i~!:~~ $~~ ~~~ ~~~ ~;ii ~!
~i~~~~ ~~~~ ;:
~:~~ ~ ~~
:~ .~
, >- ~
~ -> i ~ ~
:;f-"~ ~ n
~ ~~
i ~g
~
&
..~
I .
<J
Vi
ii:
!:&
~
~
=~
~1
~~
~a
g 2 ti:
:z'" ~ ~
~t3 gj r::.:
~ .~ i~: :z
.!:l ,...~!;:j < -, 6 : -> ~
] ~ =~ q N ~ i
5 ~ ~~ ti:r::.: fq ~ ~f ~g
.~ i ~~ ~~=~;i ;: ~i
~ ~ ~ g~--:q g ~i~~
"""t;80:: v
5 3 ~i ~ q ~
.... . A:,
.0 ~ C < --: ! ->
~ ~ -I ~ B ~ ~
~ ~ I~ ~ ~ ~ ~ :z!~
~
&
..~
I .
<J
Vi
11:
1-
Lr\
~
:=~
~1
~~
i;
15 2 ti:
:z0< ~ ~
t;~ .- :::r
,-1'Ii ~
~: :
( ....... I I
q-~
.- N
~ .11:
~~
] ~ =~
.g .~ ~~ ~~--T ~
i I ~.~
~ ,g ~
~ ~ ::i
Ii ~n
~ i ~~:~
~
~RJ->: ~ ;;j<---S~
~~-! j g ~ i-----;!t:
~ v ~
o
N rJ ~
A,:
< -i i->
~ r::: Ij:j
~ ~ ~
UJ
:z+~
:J:
.
.
~~
~>
Ei
~
d
~ ~~~o
ci
~
ci
~
ci
...... ,...
0::.......,... O::""'~ <<......."
.......t-.....J ..............J ........cd
~~i ~~i ~~~
Ell IE ~
,
,
~~j
>->,
P5 !
~
ci
~
d
I:fl~~'"
cidd
~
d
~
d
~~ ~~~~ ~g~~ ~~~~ ~~~
;;;; ;;;; ;;;; ;;; i ·
~~8.. !
~S~~ ~RJ~Q Ij:jC~~ ~.-.- ~~~~
. " >i. ~~~ N$~ g~~~ ~~
~~~~ ~~
!:&S~ ~RJ~ Ij:jr:::~ ~~~ ~~~! ~~
...... ...... ~ gi~~ ~~
1 i~~! i~~! i~~! i~~ I~~~ !;
Sl ER lEE ~ ill!
12 .i!:
19 98
~ ~ ~~
6 ~ ~..:; I:;:~ -:- 0
.~ ] @'~ ~ra=~~
~ ~ i i~ffi-:q
t- ._ ~ : _........ yor-
5 ] Mi ~ N N ~
':>. . ^,:
.D ~ <-i i->
~ ~ g~ ~ ~ ~ ~
~ ] ~~ 5 ~ ~ ~
g
] ~
.~ ~
I !
..... .-
~ .11
..... ~
1f ~
~ ~
~ i
i!:
98
!ll..(i
~~ 1:;::= ~q
~C: ~~_I'r-'"
t;j;::
~
~
Ni q ~ ~
^:,
< -!
3fl 5l
ia ~
-~j5
~, it
::t !9
;:;-,. ..
t:l '-';'
~
=~
~1
~
~
i!:
~
~
=~
~1
~ it
;:;-,. ~
d .n
!:it
=~
~~
~ ?fji!:
] ~ ~~
6 b ~..:;
'Z ._ ": ~
i ! i'~
..... .- ~
S ] ~~
1f ~ ~
~ ~ 9fl 5l
~ .;; ~ 2l ~
~ ~ -~ ~
~~
~~
>-~ ~ ~
..~ .
I .
8~
'"
.~~ ~ ~
~: I ,'_>
< -I j
q Ci 0
N
~..... "'~ ~~
N j---M-
~~
~ ;;;<~~
d q:~t;:
6 Ny :.J~
UJ
z+'"
~
~~
i~
z~ ~ ~
.~&l ~ s:
&t:
< ............... I ,
;1-
~ ,..;
..~
I -
8~
'"
~
~$->~ ~
~i2-! S ~.
_ v _
~
z
: -> >:;
:3 ~
:: : ~~ ~
~
"':< --BiZ
~ ~I'"
5i~~
!->
~ ~ S
~ ~ ~
UJ
z+Vl
:J:
..~
I -
~~
Vi
~~
ii
~ $ ~
>-~
.~Bi :s ~
bt, ,
,,-: : :-:>
0:- ~
.- ~
.....~ -:-0
l.L ,.
~ -.N
al%l->q
I"'~ M
t;=!\;-:q
Cl , ~
_ V
~
:z
>:;
N &t
10 q ~ ----EllS
:5 - I @
~ ~<-i~
. q:---KJt;:
g ~y .-~
q q q
.- ~ ~
^:,
( -:
J:;; IR ::;:
i->
~ ~ ~
UJ
;Z:+Vl
:J:
:z ~
~ ~ ~
i
~ n
~
~
t; ~
H~
~ ~~
~ ~g
~
@ ~
i @t;,
~ ~~
.. ~
~ ~~
~ ~g
i!
~I.:?
.....>
e;
~
o
~
o
~ ~~~O
o
~
d
~~ ~~~ ~~~ ~~~~ ~~m
doo ddd dddd ddd
I
:g!i!c;.. ~
~~ii ~:
~~~~ 3~-
~~~~ ~~
lip;, ~~
~i~g <>:9
h~1 i;
.. 3
~~~ ~~~ ~~~~ ~~~
.. .. il ..
~~~ t!!ij}~ ~~~~ ~~~
~~
~g ~~~ ffiijj~ ~~~
~~~
~..........
I ...............
l52t;
Ci<1"'~
..... ..... .....
5C:J 5;=-~ 5C::J'
~~ffi ~~ffi! ~iffi
iR fB 5
~
.
,
.
,
,
.
@ : ~
did
~~ ~~~~!~~~ ~re~ ~~~~
;;;;1;;; ;:: ;;;; I ·
:g!i!6..
~~~~ ~~~ ~~~ ~~~~ ~~~i ~!
i~~~ o~-
!i;~ ~.
~~~ ~~E ~~~ &l~S: ~g~~ ~
im h
~~
il -
~
;::~
e;
~
d
~ 53~RCO
@ ddo
d
g~~ gc~ ~~~ g~~
~ l52t;~ ~~~ i~~ 8~~~
2 ~F~~i~~~ -~~ ~~~~
~ :iR fB ~
~I.:? ~
1-> r:;
e; ci
~
o
g
o
~ Ql~~'-'
~ ddd
o
~~ ~~~ ~~~ ij~~ ~~~~
doo 000 000 0000
I ~
~~O.. I'
!2;::;::l'l
Q9~~ gj_
i~liJ~ 3~
~~~~ !~
~~~Sl ~~_
,~g~ ~~
~~~~ ~~
" 3
~~~ ~~~ ~~~ ~~~~
" " il
~~~ o~~ o~J:;; ~~~~
~~!9 !\l~~ ::;:~J:;; ~:9~
..... ..........
~C:J 5C::: ~Ed 5Ea
~i~ ~i~ ~~~ ~~ffi!
S2 iR fB 5
Ul '"
>::
(:1 a: ,;,
::J '"
-0 T"'" '"
~ III Q .;,
""s '6 u.. t-;"
c:: 8
~.~ III
--0 .~ il ..:.
t\j c:: ~ ~
&'~ III
~s -s
0
~'s VI
Cll~ VI
- c:: -9!
c:: ::) S
~ 8 c ~
III 0 ~
"- (.) .~ .,;
g.~ g ~ ~
..... ~ V,I VI
VI - "" c:
Cb S co ::)
CD .Qo~ 8
~ E-c::
::) "t Cll ""
~t\jg ":t
DQ..\()>4fIIIY .... 17,500
-
en
OJ
E
:3
g
C)
.-
-
-
~
~
>.
-
.-
~
Cl
OJ
C'l
ctS
~
Q.)
:>
<
-
~ 0-
N CtI
.... '" :E
~ '"
en ;:
z
4:
a:: 0
~ u:
4:
()
i.Ji C)
c .-
~ -
z :0 -
::J ctS
0 :J ~
() 0
~ OM
:;:
UJ >0 en
UJ .~ en
a:: ()T'"
u..
">~
'a' H't'ro~
~XHI8rr, J , ,'.-'-_
Igq3 TrQffic Flow Map
(AVerct;J Da; ~ 17.:frc..:)
,
... , ,.
LEVEL OF
SERVICE
A
B
C
D
E
F
LEVEL OF
SERVICE
A
B
C
D
E
F
.
.
LEVEL OF SERVICE DESCRIPTIONS
(INTERSECTIONS)
TRAFFIC FLOW QUALITY
Low volumes; high speeds; speed not restricted by other veIMcles; all signal cycles
clear with no vehicles waitin throu h more than one si al c cle,
Operating speeds beginning to be affected by other traffic; between one and ten
percent of the signal cycles have one or more vehicles which wait through more
than one si nal c cle durin eak traffic eriods.
Operating speeds and maneuverability closely controlled by other traffic; between
11 and 30 percent of the signal cycles have one or more vehicles which wait
through more than one signal cycle during peak traffic periods; recommended
ideal rural desi n standard.
Tolerable operating speeds; 31 to 70 percent of the signal cycle have one or more
vehicles which wait through more than one signal cycle during peak traffic
eriods; often used as desi n standard in urban areas.
Capacity; the maximum traffic volume an intersection can accommodate; restricted
speeds; 71 to 100 percent of the signal cycles have one or more vehicles which
wait throu h more than one si nal c cle durin eak traffic eriods,
Long queues of traffic; unstable flow; stoppages of long duration; traffic volume
and traffic speed can drop to zero; traffic volume will be less than the volume
which occurs at Level of Service E,
LEVEL OF SERVICE DESCRIPTIONS
(STREET SEGMENTS)
OPERATING CONDITIONS
Free flow; speed controlled by driver's desires, speed limits, or physical roadway
conditions.
Stable flows; operating speeds begiMing to be restricted; little or no restrictions
on maneuverabilit from other vehicles.
Stable flow; seeds and maneuverabilit more closel restricted,
Approaches unstable flow; tolerable speeds can be maintained, but temporary
restrictions to flow cause substantial drops in speed. Little freedom to maneuver,
comfort and convenience low.
Volumes near capacity; flow unstable; stoppages of momentary duration, Ability
to maneuver severel limited.
Forced flow; low 0 eratin seeds; volumes below ca acit; ueues form.
-VHIt3I~ ~
;:1\ H:Z!.~ --" . - '.
~LXl % Sexv\Q (LOS) De~nf1umS