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City of Lafayette Staff Rqx)rt
By:
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Subject:
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Background
When fhe City Council established a goal to investigate solutions to downtown congestion, you directed the Circulation Commission to develop a scope of work for a comprehensive study. At fhe time, the Commission identified the update of signal timings as a straightforward early action that could be undertaken immediately. Serendipitously a grant opportunity became available fi'om the Metropolitan Transportation Commission (MTC) for such an effort, and staff was able to obtain funding to undertake this project. This report is to update the City Council on the work that has recently been completed.
Summary of Work Done
Services fi:om TJKM Transportation Consultants were awarded to Lafayette to inventory and analyze the signal operating parameters along the Mt. Diablo Boulevard and Moraga Road corridors through fhe downtown. The consultant subsequentiy applied computer modeting to the ground traffic data to develop a set of new timing parameters aimed at increasing efficiency of the system as a whole. At the same time, the signal timings were also updated to meet current standards for ped/bike accommodation. In total, four sepai-ate timing plans were developed for the average weekday, and one for the typical weekend day. These new signal plans were subsequently implemented in the field on a trial basis to observe tiieir effect on real-time traffic operations. Incremental adjustments were then made, followed by additional field observations of traffic. This iterative process was repeated to yield signal timings that were considered to be the best balance of observed operating constraints. The final signal parameters have been in place since early April.
The attached staff report to the Circulation Commission and the accompanying project report fi'om TJKM contain more details about development of the various signal timing components, as well as a comparison of various traffic statistics before and after the signal timing update.
Next Steps
The Circulation Commission reviewed the final project report at its meeting on June 1, and indicated support for continuing tlie operation of the new signal timing plans as currently implemented in the field. Staff plans to provide the TJKM report and the updated signal plans to the consultant conducting the downtown congestion study to potentially stimulate
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discussions about enhancements and strategies that are beyond the scope of the grant-fUnded study by TJKM.
Recommendation
Receive and file.
Attachment
June 1, 2015 Staff Report to Circulation Commission, with TJKM Project Report as Attachment
2 of 2
City of Lafayette Staff Report
By: Meeting Date: Subject:
For:
Introduction
In support of the City Council's stated goal to explore traffic congestion relief options in Downtown Lafayette, staff obtained a grant to evaluate and update traffic signal coordination timing along the Mt. Diablo Boulevard and Moraga Road corridors within the downtown area. Last September the Commission received a briefing regarding existing signal operations in the study area, along with recommendations by TJKM Transportation Consultants to update and optimize them. The Coimnission supported the implementation of a field trial of the proposed updates to verify the benefits predicted by computer modeling. This staff report will present TJKM's final project report, documenting the field implementation process and the resulting outcome. Staff is seeking the Commission's support to continue operating the updated signal parameters as currently implemented in the field.
Study Background
The two study corridors consist of twelve signals- Nine on Mt. Diablo Boulevard (MDB) fi'om Dolores Drive to Brown Avenue, and three on Moraga Road from St. Mary's Road to MDB. TJKM has collected traffic data and evaluated signal operations during different times of day to comprise four peak periods during a weekday- morning commute, mid-day, after-school, and evening commute. A weekend mid-day peak is also included in the study.
In formulating its recommendations for changes, TJKM begins by evaluating individual signals for compliance witli current standards and guidelines for both vehicular operations and ped/bike accommodation. Settings that have been adjusted include yellow clearance time, minimum green time for bicycles, and "flashing-don't-walk" clearance time for pedestrians. TJKM then models the signals as a connected network to gauge the benefits of operating them as a coordinated system under traffic conditions occurring at different times of day. This effort examines the optimal cycle length, allocation of green time, and the "offset" values between signals, which help to minimize stop delay by sustaining the progression of vehicles platoons as they move through fhe corridor.
In response to traffic data and operating conditions observed in the field, TJKM is not recommending to include every study intersection in a coordinated plan for every peak traffic period under consideration. As an example, it has deteiTnined that there is little benefit to
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running in free mode, this turn is served twice every signal cycle using a "conditional service" feature, which is not compatible with coordinated mode. Staff in fact has observed that, intermittently during the evening peak period, this eastbound left-turn queue does extend back to the Dolores Drive intersection. This is especially true during times when MDB experiences a high level of traffic diverted from Highway 24. Even so, the allocations in the updated plan do provide sufficient time for this queue to clear out during most cycles. Occasionally there would be one or two vehicles held back. When the queue spills out to the left-most (No. 1) through lane, there appears to be sufficient capacity in the remaining curb (No. 2) lane to SQP/Q through traffic with no significant delay. Overall the intersection appears to be functioning as intended, and tlie coordination with adjacent signals is providing the desired benefit in ti'affic progression. I f conditions do not markedly worsen, staff believes that this is a worthwhile ti-ade-off.
Next Steps
Based on the results observed, staff recommends support by the Commission to continue operating tiie updated signal plans as currently implemented. Tlie soon-to-begin Downtown Congestion Study provides yet another opportunity for a different consultant to observe traffic conditions under the new schemes and provide recommendations for fUrther refinement i f warranted. Staff will share the TJKM final project report with that consultant, and we will soon be askuig the City Council to accept this signal timing study as complete.
Recommen dation
The Commission should support operating the new signal coordination plans as currently unplemented in the field.
Attachments
1. TJKM Final Project Report
3 of 3
\ T y Metropolitan Transportati Prepared for the
ion Commission
Ii»ftg»n^iimMini5tg|*.j
Prepared by
TJKM Transportation Consultants
May 27,2015
Deliverable #4B: Final Project Report with Benefit/Cost Analysis
Metropolitan Transportation Commission Program for Arterial System Synchronization (PASS) for the City of Lafayette
May 27, 2015
TJKM
TJKM Transportation
Consultams
Disclaimer: The information, data, analyses, and recommendations in this report reflect the date listed on the cover page. It is anticipated that as a regular part of arterial operations and system monitoring, changes may be required to the timings listed in this report, and thus this report may not reflect the conditions in the field after a certain period of time has passed.
TJKM Transportation
Consiiitants
Table of Contents
Introduction and Summary 1
Existing Conditions Review 4
Data Collect ion 4
Existing Signal System and Timing 5
Traff ic Vo lume Data 5
"Be fo re" Floating CarSurvey (Existing Estimates of Performance IVIeasures) 8
Actuated Settings Review 12
Yel low and Red Intervals 12
Pedestrian T iming 12
IVIinimum Green Interval f o r Bicycles 13
Collision History Review 14
Traffic Signal Timing Analysis and Recommendations 16
Evaluation Criteria 16
Signal T iming Analysis 16
Recommendat ions 18
Timing Plan Implementation and Evaluation 2X
Instal lat ion of GPS clocks 21
Evaluation 2 1
Benefit /Cost Ratio Analysis 30
Benefits t o Other Modes 32
Traff ic Safety Benefi t 32
Benefits t o Pedestrians 32
Benefits t o Bicyclists 32
Conclusion 32
Glossary 33
List of Appendices (Appendices are available online at www.ci.lafayette.ca.us. Go to the "Transportation" page under "Engineering" Department.)
Appendix A - Traff ic Counts
Appendix B - Detai led Floating Car Survey Worl tsheets
Appendix C - Yellow and Flash Don ' t Walk Analysis
Appendix D ~ Collision Analysis
Appendix E - Proposed Timing Sheets (After Fine Tuning and Imp lementa t ion)
Appendix F - Synchro Mode l Outputs fo r Existing and Proposed Condit ions
Appendix G - Benefi t /Cost Ratio Analysis Worksheets
List of Figures
Figure 1 : Vic in i ty M a p 3
List of Tables
Table 1 : Existing Signal Control lers, Sof tware, Cycle Lengths and Offsets 6
Tabie 2 :24 -hou r Traff ic Volumes Summary 7
Table 3: Floating Car, Mt . Diablo Boulevard, "Be fo re " Travel T ime Survey 9
Table 4 : Floating Car, M t . Diablo Boulevard be tween Dolores Drive and Lafayette Circle (West) ,
"Be fo re " Travel Time Survey 10
Table 5: Floating Car, Moraga Road f r om M t . Diablo Boulevard t o St. Mary 's Road, "Before" Travel
T ime Survey 1 1
Table 6: CA MUTCD Yel low Interval Requirements 12
Table 7: Intersect ion Collision Summary 15
Table 8: Existing and Recommended Cycle Lengths and Offsets f o r Weekday and Weekend Peak
Periods fo r M t . Diablo Boulevard and Moraga Road Corr idor 19
Table 9; T ime o f Day Signal Coordinat ion Schedule f o r Weekday and Weekend Peak Periods fo r M t .
Diablo Boulevard and Moraga Road Corr idor 20
Table 10: Floating Car, Mt . Diablo Boulevard, "A f te r " Travel T ime Survey 22
Table 1 1 : Float ing Car, M t . Diablo Boulevard be tween Dolores Drive and Lafayette Circle (West) ,
"A f t e r " Travel T ime Survey 23
Table 12: Floating Car, Moraga Road f r o m M t . Diablo Boulevard t o St. Mary 's Road, "A f te r " Travel
T ime Survey , 24
Table 13: "Before" and "Af te r " Comparison of System Measures o f Effectiveness (MOEs) fo r M t .
Diablo Boulevard 27
Table 14:"Before" and "Af ter" Compar ison of System Measures of Effectiveness (MOEs) f o r M t .
Diablo Boulevard, be tween Dolores Drive and Lafayette Circle (West) 28
Table 15: "Before" and "Af te r " Comparison of System Measures of Effectiveness (MOEs) f o r
Moraga Road 29
Table 16: Benef i t /Cost Analysis 3 i
TJKM Transportation
Consultants
In t roduct ion a n d S u m m a r y
The Me t ropo l i t an Transportat ion Commission (MTC) has in i t ia ted a program fo r t he coord ina t ion of
signals th roughou t the Bay Area called the Program fo r Arter ia l System Synchronizat ion (PASS). The
City o f Lafayette appl ied fo r and received a grant t o coord inate t raf f ic signals a long the M t . Diablo
Boulevard and Moraga Road Corr idors th rough d o w n t o w n Lafayette.
The goal o f this project is t o faci l i tate t raf f ic progression along the s tudy intersect ions and to update
signal t im ing plans to maximize operat iona l eff ic iency of the t raf f ic signals w i t h i n existing capacity
constraints. Given the d o w n t o w n project set t ing, signal t im ing must also be sensit ive t o non-auto
users of the public streets. The goal is t o reduce t ra f f ic congest ion, reduce t ra f f ic delays, reduce the
emission of harmfu l greenhouse gases, reduce automobi le and transi t t rave l t i m e along the study
corr idors, and provide safe t ra f f ic signal operat ions fo r users of all modes. The project object ive is t o
develop t raf f ic signal coordinat ion t im ing plans for weekday morning commute (a.m.), midday,
a f ternoon school pick-up (school p.m.), evening commute (p.m.) and weekend peak periods
respectively.
The twe l ve t ra f f ic signals tha t are funded in t he City of Lafayette as a par t of this project are l isted
be low and shown in Figure 1. The Ci ty-owned t ra f f ic signals have 170 type t ra f f i c contro l lers, and
opera te w i t h Bl Tran 200 SA and 233 RV t ra f f ic cont ro l le r sof tware.
The fo l l ow ing is a list o f t raf f ic signals tha t are inc luded fo r the project :
Mt . Diablo Boulevard Traff ic Signal System
1 . M t . Diablo Boulevard/Dolores Dr ive-Mounta in V iew Drive
2. M t . Diablo Boulevard/Happy Valley Road
3. M t . Diablo Boulevard/Dewing Avenue
4. Mt . Diablo Boulevard/Lafayet te Circle (West)
5. Mt . Diablo Boulevard/Oak Hill Road-Lafayette Circle (East)
6. Mt . Diablo Boulevard/Moraga Road
7. Mt . Diablo Boulevard/First Street
8. Mt . Diablo Boulevard/Second Street
9. Mt . Diablo Boulevard/Brown Avenue
Moraga Road Traff ic Signal System
10. Moraga Road/Moraga Boulevard
1 1 . Moraga Road/Brook Street/School Street
12. Moraga Road/St. Mary 's Road/Herman Drive
TJKM conducted an analysis of exist ing condi t ions, including t raf f ic vo lume and coll ision data, signal
t i m i n g and sett ings. The Synchro t raf f ic models developed as part of t he exist ing condi t ions analysis
were used as t he basis fo r developing t he proposed signal coord inat ion plans, wh ich included the
evaluat ion o f signal grouping, cycle lengths, spli ts, of fsets, and t ime-of -day opera t ion . Signal t im ing
parameters re lated t o pedestr ian and bicycle movements w e r e also updated. The proposed t im ing
plans were presented t o t he City Staff f o r init ial feedback, pr ior t o f ie ld imp lementa t ion and
op t im iza t ion . Floating car surveys were conducted before and af ter imp lementa t ion o f new signal
t imings t o document actual change in t ra f f ic condi t ions.
Page 1
Deliverable ff4B: Final Project Report witii Beneftt/Cost Ar^alysis, City of Lafayette May 27,2015
This repor t provides a summary of t he exist ing condi t ions and recommended t imings developed fo r
t he project , a long w i t h the result ing improvements in various measures of effect iveness f o r t h e
study corr idors.
Page 2
Deliverable 04B: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27, 2015
^ Vicinity IVlap
Figure 1
Exist ing Cond i t ions R e v i e w
Data Collection
This repor t contains data provided by t he City of Lafayette and col lected by TJKM Transportat ion
Consultants in t he f ie ld. TJKM Transpor tat ion Consultants col lected t he fo l l ow ing data f r o m the City:
• Traff ic signal t im ing sheets
• Historical t ra f f ic counts
• Intersect ion As-Built plans
• Three-year intersect ion coll ision history
• Synchro fi les w i t h exist ing t im ing in format ion
TJKM col lected t he fo l low ing data in t he f ie ld t o document and model exist ing condi t ions:
• Manua l t u rn ing movemen t counts and lane geomet ry for each study in tersect ion fo r t he
weekday a.m., midday, school p.m., and p.m. and weekend peak per iods. These counts
include vehicles, pedestr ians, and bicyclists (See Appendix A).
• 24-hour Average Daily Traff ic (ADT) counts at f ive locations w i th in study corr idors (See
Appendix A).
• Floating car runs in each d i rect ion fo r each of the f ive peak periods fo r bo th s tudy corr idors
(See Appendix B).
• Field review tha t ident i f ied intersect ions that are oversatura ted, signif icant di f ferences in the
propor t ions of trucks and buses f r o m defaul t values in Synchro, major dr iveways and
unsignalized intersections t ha t may af fect arr ival rates and patterns at signalized
intersect ions, parking maneuvers, pedestr ian act iv i ty, and o ther t ra f f ic pat terns tha t may
af fect t he abi l i ty to coord inate signals in t he system.
• Field ident i f icat ion of study intersect ions w i t h uneven vehicle d is t r ibut ion in t ravel lanes.
• Field ident i f icat ion of locat ions whe re t he le f t - turn o r right t u rn queue exceeds t he storage
length o f t he tu rn ing lane.
The col lected and compi led data was used t o develop t ra f f ic models fo r exist ing condi t ions.
Collision data at t he signalized intersect ions were col lected and rev iewed w i t h respect t o accident
pat terns t ha t may be correct ib le by changing basic signal sett ings and improv ing coord inat ion .
Addi t ional ly , exist ing signal sett ings were reviewed t o ident i fy potent ia l changes t ha t might reduce
delay t o vehicles, pedestr ians and bicyclists. Such sett ings include clearance intervals f o r vehicles,
pedestr ians and bicycles; vehicle de tec t ion gap and extension sett ings; cycle lengths as inf luenced by
m i n i m u m and max imum green t imes; and phase sequence.
Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette
Page 4
May 27, 2015
Existing Signal System and Timing
Current ly, all o f t he study t ra f f ic signals are actuated, and signal in terconnect Is in place on t he
Moraga Road corr idor , and on t he M t . Diablo Boulevard corr idor be tween Lafayette Circle Wes t and
First Street. Table 1 shows the existing signal contro l lers, so f tware , and cycle lengths and offsets
dur ing each peak period fo r each study intersect ion tha t is operat ing in coord ina t ion mode. Those
not operat ing in coord inat ion mode are noted as running " f ree" .
Traffic Volume Data
TJKM col lected t he tu rn ing movemen t counts on Tuesday, September 10, 2013 when schools were in
session at all s tudy intersections. The weekend counts were col lected on Saturday, September 28,
2013. Appendix A contains the vehicle, pedestr ian, and bicycle counts f o r the s tudy intersect ions.
Turn ing movemen t counts were entered in to t he Synchro model f o r the exist ing condit ions analysis.
In addit ion, 24-hourtube counts were collected fo r seven days between Saturday, September 7, 2013
and Friday, September 13, 2013 at the fol lowing five locations:
1. M t . Diablo Boulevard be tween Lafayette Circle (West) and Dewing Avenue
2. M t . Diablo Boulevard be tween Moraga Road and Oak Hill Road/ Lafayette Circle (East)
3. M t . Diabio Boulevard be tween First Street and Moraga Road
4. M t . Diablo Boulevard be tween Second Street and First Street
5. Moraga Road between School /Brook Street and Moraga Boulevard
The 24 -hou r t ra f f i c vo lumes are summar i zed in Table 2 be low. Deta i led resul ts a long w i t h
graphs o f 24 -hour t ra f f i c vo lumes are p resen ted in Appendix A. The 24-h r t r a f f i c vo lumes
w e r e used t o d e t e r m i n e t h e peak per iods fo r co l lec t ing t u r n i n g m o v e m e n t coun ts and f o r
p rov id ing a t i m e of day schedu le f o r t h e p roposed coo rd ina t i on plans.
In add i t ion to the vo lume counts summar ized in Table 2, TJKM conducted f ie ld observat ions t o
ident i fy operat iona l parameters unique t o the s tudy corr idors, such as unconvent iona l phase
sequencing, condi t ional service, over lap phases, and saturat ion f l ow rates. Those parameters are
impor tan t in accurately model ing existing t ra f f ic condi t ions as wel l as develop ing t im ing plans t ha t
respond t o t ra f f ic patterns in t he f ie ld .
Deliverable ff4B: Final Project Report witti Benefit/Cost Analysis, City of Lafayette
Page 5
May 27, 2015
TJKM Transportacion
Cofisui tents
TabEe 1: Existmg Signal Controllers, Software, Cycle Lengths and Offsets
(i
2
3
4
5
6
7
S
9
10
11
12
Notes "Free'
Drive-IVlountain View Drive
Mt. Diabio Boulevard/
Happy Valley Road
Mt. Diablo Boulevard/
Dewing Avenue
Mt. Diablo.Boulevard/
Lafayette Circles {West)
Mt. Diablo Boulevard/Oak Hill
Road-Lafayette Circles (East)
Mt. Diablo Boulevard/
Moraga Road
Mt. Diablo Boulevard/
1st Street
Mt. Diablo Boulevard/
2nd Street
Mt. Diablo Boulevard/Brown
Avenue-AI manor Lane
Moraga Road/ Moraga Boulevard
Moraga Road/School Street-
Brook Street
Moraga Road/St. Mary's Road-
Herman Drive
170E
17QE
170£
170E
170E
170E
170
170
170E
170E
170E
233 RV
233 RV
233 RV
200 SA
233 RV
233 RV
200 SA
200 SA
233 RV
233 RV
233 RV
No
No
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Information provided above is correct as of December 2013. denotes intersection not operating in signal coordination mode, but is actuated based on
Free
Free
Free
110
110
110
Free
Free
110
110
Free
demand.
Free
Free
Free
43
37
0
Free
Free
9
99
Free
Free
Free
Free
120
120
120
Free
Free
120
120
Free
Free
Free
Free
100
0
0
Free
Free
107
93
Free
Free
Free
Free
120
120
120
Free
Free
120
120
Free
Free
Free
Free
100
0
0
Free
Free
107
93
Free
Free
Free
Free
Free
120
120
120
Free
Free
120
120
Free
Free
Free
Free
Free
103
0
0
Free
Free
107
93
Free
Free
Free
Free
110
110
110
Free
Free
110
110
Free
Free
Free
Free
35
0
0
Free
Free
9
99
Free
Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette
Pages
IViay 27, 2015
Table 2:24-hour Traffic Volumes Summary
A.
B.
E.
Mt. Diablo Boulevard Weekday (M-F) 7,448
(west of Lafayette Circle (West)) Weekend (S-S) 6,055
Mt. Diablo Boulevard Weekday (M-F) 8,907
(west of Moraga Road) Weekend (S-S) 8,025
Mt. Diablo Boulevard Weekday (M-F) 12,800
(west of First Street) Weekend (S-S) 11,152
Mt. Diablo Boulevard Weekday (M-F) 6,809
(east of First Street) Weekend (S-S) 5,040
Moraga Road Weekday (M F) 9,373
(south of Moraga Boulevard) Weekend (S-S) 9,055
Notes:
Data w a s col lected in month of S e p t e m b e r 2 0 1 3
* v p d - veh ic les per day
Deliverable MB: Fmal Project Report with Benefit/Cost Analysis, City of Lafayette
"Before" Floating Car Survey (Existing Estimates of Performance IVIeasures)
A f loat ing car run covers a one-way t r ip o f t he def ined length of a study corr idor . These runs
capture t he t rave l t ime , speed, s topping t i m e , number o f stops, and o ther delays on an individual
d i rect ion along t h e study corr idor. Four f loat ing car runs were conducted dur ing t h e weekday a.m.,
midday, school p.m., p.m. and weekend peak periods fo r the "Be fo re" and "A f t e r " surveys. The
weekday and weekend "Before" surveys were conducted In t he mon th September 2013 afong M t .
Diablo Boulevard and Moraga Road and the "A f te r " surveys were conducted in t he mon th of Apr i l ,
2015.The f loat ing car survey data were analyzed t o obta in overal l averages o f t rave l t ime , delay,
and computed t ravel speed for t he ent i re length of each corr idor. These parameters help t o
qual i tat ively describe the existing t raf f ic condit ions along the corr idors, specif ically, how wel l
p latoons of vehicles are able t o move th rough a corr idor and the corresponding a m o u n t of
congest ion/delay encountered.
The results of t he f loat ing car surveys conducted under existing condi t ions are shown in Tables 3 ,4
and 5. Existing condi t ions surveys are t e rmed as "Be fo re" surveys. The results of t he "Be fo re"
f loat ing car surveys w i l l be compared t o the "A f te r " f loat ing car surveys t ha t are conducted a f ter
imp lementa t ion o f t he proposed signal t im ing plans. The f loa t ing car worksheets are contained in
Appendix B.
The M t . Diablo Boulevard corr idor is d iv ided in to sub-sections f o r t h e purpose of f loat ing car
surveys. This is done t o account f o r t he var ia t ion in t raf f ic vo lumes and pat terns observed on these
sub-sections dur ing t he d i f fe rent t imes of day. Current ly, some intersect ions are coord inated and
others are no t (see Table 1). The sub-sections are helpful in seeing the effects of t he new signal
t imings in te rms o f improvements in coord inat ion and benef i ts of coord inat ing signals tha t are
previously runn ing independent ly ( free).
The f loat ing car surveys were conducted fo r t he fo l low ing segments along M t . Diablo Boulevard fo r
each o f t he f ive peak periods:
• A . M . Peak Period: M t . Diablo Boulevard, be tween Dolores Drive and First Street fO.63
miles)
• Midday Peak Per iod: M t . Diablo Boulevard, be tween Oakhil l Road and First Street 10^22
miles)
• School P.M. Peak Period: M t . Diablo Boulevard, be tween Dolores Drive and Brown Avenue
fO.97 miles)
• P.M. Peak Per iod: M t . Diablo Boulevard, be tween Dolores Drive and Brown Avenue (0.97
miles)
• Weekend Peak Per iod: M t . Diablo Boulevard, be tween Dolores Drive and First Street 10.63
mi lesl
The f loat ing car surveys were conducted fo r t he fo l lowing segment along Moraga Road for each of
the f ive peak per iods:
• Moraga Road, be tween M t . Diablo Boulevard and St. Mary's Road/Herman Drive fO.43
miles)
Deliverable MB: Final Project Report witii Ber)efit/Cost Arjaiysis, City of Lafayette
Pages
May 27, 2015
Table 3: Floating Car, Mt. Diablo Boulevard, "Before" Travel Time Survey
1:̂
5:̂
5:,
3::
3::
1:^
6::
6::
4:i
Mt. Diablo Boulevard,
between
Dolores
Drive and Brown
Avenue*
Midday^
1.05
1:07
2:37
3:07
1:27
1:29
1:02
3:19
3:45
1:58
,49
:45
;41
;56
;38
;21
;41
;26
22
;02
1
5
4
3
3
1
6
4
3
15
9
10
10
11
11
8
9
9
10
64%
46%
53%
40%
44%
6 1 %
52%
59%
49%
EB School P.M.^
P.M.^
Weekend"
A.M."
Midday^
WB School P.M.^
P.M.^
Weekend" Notes:
^Average s p e e d along the corridor including stop de lays , not reflective of actual s p e e d s of vehic les whi le moving.
^Average n u m b e r of s tops m a d e by a c a r from all the travel t ime runs col lected on the study corr idors including s tops at
red lights as wel l as o ther stops b e t w e e n intersect ions due to congest ion.
^Signal Delay as percentage of travel t ime .
"A.M. and W e e k e n d Peak Periods - Floating c a r runs b e t w e e n Dolores Drive and First Street .
^Midday Peak Period - Floating car runs b e t w e e n Oakhill Road and First Street.
^School P.M. and P.M. Peak Periods - Floating car runs b e t w e e n Dolores Drive and Brown A v e n u e .
* T h e r e a re nine (9) signalized intersect ions a long this corr idor.
Deliverable MB: Final Project Report with Beriefit/Cost Analysis, City of Lafayette
Page 9
May 27, 2015
Table 4: Floating Car, Mt. Diablo Boulevard between Dolores Drive and Lafayette Circle (West),
"Before" Travel Time Survey
A.M. 0;30 1:15 1 14 40%
Sciiool Mt. Diablo
EB P.M. 0:38 1:34 2 11 40%
Bouievard, EB
P.M. 0:51 1:44 1 10 49% between
Weekend 0:30 1:25 1 13 36% Dolores Drive
Weekend 0:30
and Lafayette A.M. 0:34 1:25 2 12 4 1 %
Circle WB
School 0:39 1:45 1 12 • 37%
(West)* WB P.M. P.M. 1:32 2:22 2 8 65%
Weekend 0:18 1:15 1 16 24%
Notes:
^Average speed along tlie corridor including stop delays, not reflective of actual speeds of vehicles while moving. ^Average number of stops made by a car from all the travel time runs collected on the study corridors including stops at red lights as well as other stops between intersections due to congestion. ^Signal Delay as percentage of travel time. *There are four (4) signalized intersections along this corridor. The corridor was not coordinated for the weekday midday peak period based on analysis. Hence, floating car survey for this peak period is not provided.
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May 27,2015
Table 5: Floating Car, Moraga Road from Mt. Diablo Boulevard to St. Mary's Road, "Before" Travel Time Survey
NB
Moraga Road*
SB
A.M. 1:43 2:54 2 10 59%
Midday 1:48 2:54 2 9 62%
School P.M. 2:12 3:02 2 12 73%
P.M. 0:43 1:52 2 14 38% Weekend 1:12 2:22 2 11 5 1 %
A.M. 0:14 1:28 1 18 16%
Midday 0:21 1:28 1 18 24% School P.M. 1:35 3:10 2 9 50%
P.M. 0:35 1:39 1 16 35% Weekend 0:13 1:15 2 21 17%
Notes;
^Average speed alongtlie corridor including stop delays, not reflective of actual speeds of vehicles while moving. ^Average number of stops made by a car from all the travel time runs collected on the study corridors including stops at red lights as well as other stops between intersections due to congestion. ^Signal Delay as percentage of travel time. *There are four (4) signalized intersections along this corridor.
The f loa t ing car survey data suggest tha t t raf f ic progression th rough the s tudy corr idors can be
improved . On M t . Diablo Boulevard, there appears t o be a not iceable degree o f signal delay
be tween Dolores Drive and First Street. In fact , this delay as a percentage of t o ta l t ravel t ime
th rough the corr idor is consistent ly around 50% fo r most of t he p e a k t i m e periods. This is not
surpr is ing since t ra f f ic vo lumes are known t o be at or approaching saturat ion levels at t he
intersect ions w i t h Oak Hill Road, Moraga Road, and First Street. Signal delay is even higher on t he
Moraga Road cor r idor at certa in peak t imes, especially in the no r thbound d i rect ion dur ing t h e a.m.
peak and school p.m. peak t imes. Signal delays account fo r over 60% of t he overal l t ravel t i m e .
Traff ic progression on M t . Diablo Boulevard east o f First Street is not iceably be t te r by compar ison.
In t he eastbound d i rect ion, signal delays are general ly less than 40% o f t ravel t ime . There is sl ightly
higher delays going wes tbound in to t he d o w n t o w n core, w i t h not iceable delay in t he school p.m.
peak.
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May 27,2015
Actuated Settings Review
TJKM rev iewed the exist ing actuated t im ing settings at the study intersect ions t o de te rmine where
sett ings could be updated t o meet cur rent standards, minimize delay, and t o enhance pedestr ian
and bicycle safety. The fo l low ing methodologies were used for t he review of pedestr ian and bicycle
t imings, ye l low and red intervals, and m i n i m u m green intervals.
j Yellow and Red Intervals
i The ye l low intervals fo r all movements were reviewed and revised accordingly t o be consistent w i t h
the CA MUTCD 2012 requi rements, as shown in Table 6.
Table 6: CA MUTCD Yel low In terva l Requi rements
25 3.0
30 3.2
35 3.6
40 3.9
45 4,3
50 4.7
55 5.0 Source: Table 4D-102 (CA). Minimum Yellow Change
Interval Timing, CA MUTCD 2012 Edition
All bu t one study intersect ion current ly meet the guidel ines fo r ye l low clearance t ime . Only a minor
ad jus tment in ye l low t ime is necessary at M t . Diablo Boulevard/Brown Avenue t o meet MUTCD
guidel ines. Append i x C shows the exist ing, calculated, and proposed changes t o t he yel low interval
fo r all study intersect ions.
Current ly, t he red clearance intervals range f r o m 0.0 t o 2,5 seconds at the s tudy intersect ions, w i t h
most movements having an all red inten/a l of 1.0 seconds. The CAMUTCD indicates t ha t all red Is
not requi red, a l though general ly, red clearance intervals range f r o m 0.0 t o 2.0 seconds. Based on
TJKM's review, no changes t o red t imes are recommended at this t ime .
Pedestrian Timing
As part o f t he analysis, TJKM rev iewed the m i n i m u m walk interval and clearance intervals f o r all
study intersect ions t o ident i fy locations where the wa lk in terval and Flashing Don ' t Wa lk (FDW)
interval should be adjusted t o meet CA MUTCD standards. CA MUTCD advises t ha t t he walk interval
should preferably be 7 seconds in length so tha t pedestr ians wi l l have adequate oppor tun i t y to
leave the curb or shoulder before t he pedestr ian clearance t i m e begins. If pedestr ian vo lumes and
characteristics do no t requi re a 7-second walk in terval , wa lk intervals as shor t as 4 seconds may be
used. Current ly, t h e s tudy In tersect ions have a m i n i m u m wa lk t i m e rang ing f r o m 5-9 seconds,
wh ich mee t t h e CA MUTCD s tandards .
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The f o l l o w i n g f o r m u l a was used t o d e t e r m i n e t h e m i n i m u m length o f t i m e f o r t h e FDW
in te rva l :
(Shortest curb — to - curb distance of crosswalk)(ft) FDW (sec) = 7^ - Yellow (sec) - All Red (sec)
3 . 5 ' y walking time
It should be no ted tha t pedestr ian crossings are general ly associated w i t h vehicular phases except
when exclusive pedestr ian scramble phase is prov ided. The "wa lk " and FDW Intervals f o r a
pedestr ian crosswalk related t o a vehicular phase const i tutes the m in imum split (or m i n i m u m green
t ime al locat ion) fo r tha t phase. Increase in walk or f lashing don ' t wa lk intervals w i l l increase the
m i n i m u m spli t f o r that movement . In some cases, th is "over-al locates" green t i m e in t he context of
vehicle t raf f ic demand of tha t movemen t and can worsen the level o f service fo r o the r movements
at t ha t intersect ion, depending on the i r demand and wa i t t ime .
Append ix C shows the existing and proposed FDW intervals w i t h inadequate exist ing FDW intervals
h ighl ighted. TJKM recommends changing twen ty -one crossing intervals at twe l ve Intersections in
order t o meet t he CA MUTCD standard.
Minimum Green Interval for Bicycles
M i n i m u m Green Interval is the m i n i m u m durat ion of green tha t must be displayed fo r a given
phase. Current ly, the study intersect ions operate w i t h a range of m i n i m u m green t imes f r o m 2 t o
16 seconds, w i t h most left t u rn movements having a m in imum green t i m e of 4 seconds and most
th rough movements having a m i n i m u m green t i m e of 10 seconds.
Accord ing to CA MUTCD, t he m in imum phase length required fo r bicycle t im ing is t he sum o f the
m i n i m u m green t im ing plus ye l low t im ing plus all red t im ing , as is de te rm ined by t h e fo l l ow ing
equat ion :
Gmin + Y + Rclear > 6 SeC + (W+6f t ) / l 4 .7 f t / seC
Whe re :
Gmin = Length of m i n i m u m green interval (sec)
Y =:Length of ye l low interval (sec)
Rciear =Length of red clearance interval (sec)
W ^Distance f r o m l imi t l ine t o fa r side o f last conf l ic t ing lane (ft)
This fo rmu la aims t o ensure tha t a bicycle is able t o clear the intersect ion w i th in t he m i n i m u m
green, ye l low and red clearance t imes al located fo r t ha t d i rect ion of t rave l . Based on t he above
considerat ion, changes t o m i n i m u m green t imes were proposed at eleven intersect ions. Append ix
C contains t he proposed changes t o m i n i m u m green t imes at each intersect ion.
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May 27,2015
Collision History Review
Collisions repor ted at the study Intersections along M t . Diablo Boulevard and Moraga Road w e r e
obta ined f r om the City of Lafayette database fo r a per iod of t w o years f r o m June 2010 t o December
2011 , and f r o m January 2013 t o June 2013. Data fo r 2012 as available f r o m the State is incomplete .
Hence, this l imi ted list was not included in the analysis. Collisions tha t occurred w i th in 150 fee t o f
an Intersect ion w e r e considered as occurr ing at t he intersect ion. Review o f col l is ion analysis helps
t o de te rmine if some of the collisions t ha t occur at the intersect ions are a t t r ibu tab le t o signal
t imings. For example, a higher number of rear-end coll ision can somet imes occur due t o
insuff ic ient ye l low change interval at t he intersect ions. Similarly, r ight-angle coll isions can occur
due t o insuff ic ient red clearance interval .
The coll ision rates at the intersections along the s tudy corr idors were compared w i t h the s ta tewide
mean coll ision rates fo r roadways and intersect ions w i t h simi lar characterist ics. Table 7 summarizes
the number of collisions involving vehicles, pedestrians and bicyclists t ha t we re repor ted at t he
study intersect ions dur ing the two-year analysis per iod. Append ix D contains t he comple te dataset
used t o conduct t he coll ision analysis, Including coll ision reports received f r o m the City. As
indicated in Table 7, t he intersect ion coll ision rates are be low state average at all intersect ions
w i th in t he s tudy area.
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Deliverable ff4B: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27, 2015
TJKPJi Trans porKttcn
Consultants
Table 7: Intersection Collision Summary
1 Mt. Diablo Boulevard/Dolores Dr.-
Mountain View Dr. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0.55 No
2 Mt. Diablo Boulevard/Mappy Valley Road 1 0 0 1 0 0 0 0 0 0 0 0 1 0 0 1 0.08 0.55 No
3 Mt. Diablo Boulevard/Dewing Avenue 0 0 0 0 0 0 1 1 0 0 0 0 0 0 1 1 0.10 0.55 No
4 Mt. Diablo Boulevard/Lafayette Circle
(West)
Mt. Diablo Boulevard/Oak Hili Rd-Lafayette
Circle (East)
0 1 0 1 a 0 0 1 0 0 0 0 1 1 0 2 0.22 0.55 No
5
Mt. Diablo Boulevard/Lafayette Circle
(West)
Mt. Diablo Boulevard/Oak Hili Rd-Lafayette
Circle (East) 1 0 1 2 0 0 0 0 0 0 0 0 1 0 1 2 0.13 0.55 No
6 M t Diablo Boulevard/Moraga Road 0 0 1 . 1 0 0 0 0 1 1 0 2 1 1 1 3 0.13 0.55 No
7 Mt. Diablo Bouleva rd/ lst Street 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0.05 0.55 No
8 Mt. Diablo Boulevard/2nd Street 1 0 0 1 0 0 0 0 0 0 0 0 1 0 0 1 0.11 0.55 No
9 Mt. Diablo Boulevard/Brown Avenue-
Atmanor Lane 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0.55 No
10 Moraga Road/Moraga Boulevard 0 0 0 0 2 0 0 2 1 0 0 1 3 0 0 3 0.20 0.55 No
11 Moraga Road/Brook Street 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0.55 No
11 Moraga Road/School Street 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 0.06 0.55 No
12 Moraga Road/St. Mary's Rd-Hernnan Drive 1 0 0 1 0 0 0 0 . 1 0 0 1 2 0 0 2 0.14 0.55 No
Totals 4 1 2 7 3 0 1 4 5 1 0 6 12 2 3 17
Notes:
ICR = 1000000*A / {365n*ADT) ICR=0b3enred collision rate; Number of Accidents/Vehicles luilies Travelled A = Number of collisions over study period T = Total number of years over which intersection accidents were collected; June 2010 to December 2011 and January 2013 to June 2013 = 2 years ADT = Average Daily Intersection Traffic
Deliverable MB: Fmal Project Report with Benefit/Cost Analysis, City of Lafayette
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May 27,2015
Traff ic Signal T iming A n a l y s i s a n d R e c o m m e n d a t i o n s
Tiie pr imary goal o f t he t im ing analysis is to develop t raf f ic signal coord inat ion t im ing plans fo r the
weekday a.m., midday, school p.m. and p.m. peak periods and weekend peak per iod to reduce
t ra f f ic congest ion, reduce t ra f f ic delays, reduce the emission of harmfu l greenhouse gases, reduce
automobi le t ravel t ime , and provide safe t raf f ic operat ions fo r users of all modes along the study
corr idors.
Evaluat ion Cr i ter ia
The fo l low ing were considered in the evaluat ion of t he exist ing t im ing plans and the deve lopment
of the proposed t im ing plans.
• Average t rave l t ime , average s top delay and average stops.
• Lead - lag and split phasing sequences were rev iewed t o de te rmine instances where i t may
improve the eff ic iency o f the coord inat ion system. Proposed changes t o t he existing lead-
lag sequences were discussed w i t h City staff.
• Level o f Service (LOS) and saturat ion f lows were rev iewed by lane groups and approaches
fo r each intersect ion.
• Progression pr ior i ty was de te rmined based on t ra f f ic vo lumes per approach.
• Peak per iod fo r t ime o f day coord inat ion plans was based on t he average daily t raf f ic
vo lume (ADT) analysis.
• Progression bandwidths were selected t o maximize t he eff ic iency o f t he coord inated t im ing
plans.
• Capacity evaluat ion was based on an analysis of queuing and degree o f saturat ion fo r each
lane g roup , approach, and cycle lengths.
• Signal t imings assume accommodat ion of pedestr ian and bike clearance per CA MUTCD
2012.
Signal Timing Analysis
The fo l low ing steps out l ine t he signal t im ing analysis in order t o develop recommendat ions fo r new
or updated coord inated signal opera t ion on t he study corr idors.
Step 1 : Mode l deve lopment
This task includes the deve lopment of a base map using an aerial pho to tha t covers ail o f the study
intersect ions.
The Synchro 8.0 compute r so f tware was used t o mode l t he existing operat ing condi t ions on the
study corr idors. This task includes t he input of tu rn ing movemen t count data in to t he mode l . Field
data such as saturat ion f l ow rates, ini t ia l lost t imes, lane ut i l izat ion and results f r o m the t ravel t i m e
survey were used t o cal ibrate t he model parameters so t ha t t he s imulat ion results repl icated the
observed f ie ld condi t ions in t he ne two rk as accurately as possible. It Is impossible t o precisely
ref lect all var iat ions o f random factors t ha t affect t ra f f ic pat terns. Fur thermore, t he s tudy corr idors
include many unconvent iona l signal phasing and sequencing tha t cannot be repl icated by standard
compu te r so f tware .
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Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27,2015
Step 2: Signal groupinR
The natura l cycle length is t he o p t i m u m cycle length f o r an intersect ion if it w e r e t o opera te f ree
(uncoord inated) . The coordinatabi l i ty fac tor measures the desirabi l i ty o f coord inat ing t w o adjacent
t raf f ic signals and is based on t rave l t ime , storage space, p ropor t ion of t ra f f ic In t he p la toon , t he
main s t reet t ra f f i c vo lume, and natural cycle length dif ferences be tween adjacent intersect ions. A
coordinatabi l i ty factor above a thresho ld of 50 indicates that t w o adjacent t ra f f ic signals are likely
t o benef i t f r o m coord inat ion .
As par t o f t he signal t i m i n g process, t h e na tura l cycle lengths fo r each in te rsec t ion and t h e
coordinatabi l i ty factors fo r t he signals in the ne two rk were reviewed t o de te rm ine t he range of
cycle lengths t o use in the opt imizat ion process, and also which groups of signals w o u l d benef i t
most f r o m coord inat ion.
Step 3: Progression movemen t de termina t ion
This refers t o progressing one o r both di rect ions o f a two -way ar ter ia l dur ing coord inat ion .
Progression preferences are d ic ta ted by d i rect ional t raf f ic d is t r ibut ion. If t ra f f ic is balanced in both
di rect ions, a balanced bandwid th is selected t o provide equal preference fo r bo th d i rect ions.
Bandwidth denotes a " w i n d o w " of green t ime whe re a p la toon of vehicles may move th rough the
corr idor w i t h o u t stopping.
For this study, progression pr ior i ty was set w i t h t he object ive of maximizing bandwid th wh i le
min imiz ing delay fo r le f t - turn movements .
Step 4 : Phase sequence evaluat ion
Leading and lagging le f t - tu rn phasing and sequent ia l changes in spl i t phases w e r e rev iewed. This
was done w i t h t he object ive t o improve the eff ic iency of signal opera t ion on t he corr idors. Leading
or lagging le f t - turn phasing can be in t roduced t o maximize progression bandw id th .
Left-turn lead/lag phasing sequence was selected and tested fo r each t ime period fo r all intersections
w i t h pro tec ted lef t - turns.
Step 5: Signal t im ing opt imizat ion
Based on t he natura l cycle lengths o f t he intersect ions in the ne twork , a cycle length range was
specif ied fo r opt imizat ion. The op t im iza t ion process also included test ing o f var ious splits and
offset. Higher cycle lengths prov ide be t te r progression fo r t he corr idor , but result in the increase in
side s t reet or overal l intersect ion delay and increase wa i t ing t ime fo r pedestr ians. Lower cycle
lengths reduce side street delay bu t may no t prov ide adequate green t i m e t o t he coord inated
phases along the main line. This may result in h igher saturat ion/congest ion, delay, and queu ing
along t h e corr idor.
Synchro so f tware was uti l ized fo r the op t im iza t ion process. The splits and o f fse t opt imizat ions were
conducted f o r t h e weekday a.m., midday, school p.m., and p.m. and weekend peak periods. Once the
cycle lengths w e r e selected, deta i led r e c o m m e n d e d t i m i n g plans, t o inc lude rev iew o f spl i ts and
of fsets w e r e deve loped and w e r e presented t o City Staf f and t he City's Consul tant Traf f ic Engineer
f o r t he i r rev iew.
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Deliverable MB: Final Project Report witii Benefit/Cost Analysis, City of Lafayette May 27, 2015
TJKM Transportation
Consuitants
1 i
Recommendations
Tables 8 and 9 summarize the proposed signai coord inat ion groupings along the t w o study
corr idors at d i f fe ren t t imes o f day. Current iy on M t . Diablo Boulevard, the signals are coord inated
between Oak Hill Road and First Street dur ing all f o u r week-day peak periods and the weekend
Saturday peak. TJKM proposes to add the adjacent f o u r signals to the west , be tween Lafayette
Circle (West) and Dolores Drive t o this coord inated system fo r the morn ing , school pick-up,
evening, and weekend peaks. These intersect ions wi l l operate " f ree " similar t o exist ing condi t ions
dur ing the midday peak per iod.
To t he east of t he existing coord inated system, TJKM recommends adding Second Street and Brown
Avenue to t he coord inated system f o r t h e school pick-up and evening peak periods only. These
intersections wi l l operate " f ree" similar t o existing condit ions at all o ther t imes.
On Moraga Road, the current signals are coord inated be tween M t . Diablo Boulevard and
Brook/School Street f o r all study peak periods, TJKM proposes t o mainta in t he coord inated system
as exist ing w i t h St. Mary 's Road-Herman Drive operat ing " f r e e " at ali t imes.
As ment ioned previously, the decision t o add intersect ions t o the coord inated system and the
groupings of intersections w i th varying cycle lengths w i th in the system is based on a combinat ion o f
evaluat ion of t he coordinatabi l i ty o f the intersect ions, the i r levels of service, t he resul t ing measures
of effect iveness, and weighing the known t rade-of fs o f runn ing an intersect ion in coord inated mode .
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Deliverable #46; Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27,2015
Table S: Existing and Recommended Cycle Lengths and Offsets for Weekday and Weekend Peak Periods for Mt. Diablo Boulevard and
Moraga Road Corridor
^ Mt. Diablo Boulevard/Dolores Existing
Drive-Mountain View Drive Proposed
^ Mt. Diablo Boulevard/ Existing
Happy Valley Road Proposed
2 Mt. Diablo Boulevard/ Existing
Dewing Avenue Proposed
^ Mt. Diablo Boulevard/ Existing
Lafayette Circles (West) Proposed
^ Mt. Diablo Bouievard/Oak Hili Existing
Road-Lafayette Circles (East) Proposed
g Mt. Diablo Boulevard/ Existing Moraga Road Proposed
7 Mt. Diablo Boulevard/lst Street Proposed
g Mt. Diablo Boulevard/ Existing
2nd Street Proposed
g Mt. Diablo Boulevard/ Existing
Brown Avenue-AI ma nor Lane Proposed
Moraga Road/ Existing
Moraga Boulevard Proposed
Moraga Road/ Existing
School Street-Brook Street Proposed
Moraga Road/ Existing
St. Mary's Road- Herman Drive Proposed
Free - Free - Free
100 74 Free - 100
Free - Free - Free
100 18 Free - 100
Free - Free - Free
100 29 Free - 100
Free - Free - Free
100 20 Free - 100
110 43 120 100 120
120 113 126 116 126
110 37 120 0 120
120 101 126 119 126
110 0 120 0 120
120 92 126 101 126
Free - Free - Free
Free - Free - 60
Free - Free - Free
Free - Free - 120
110 9 120 107 120
120 48 126 88 126
110 99 126 93 126
120 45 126 73 126
Free - Free - Free
Free - Free - Free
- Free - Free -
97 100 90 100 53
- Free - Free -0 100 0 100 40 - Free - Free -
20 100 12 100 4 1
- Free - Free -28 100 15 100 50
100 120 103 110 35
71 120 30 120 53
0 120 0 110 0
60 120 39 120 41
0 120 0 110 0
39 120 32 120 21
- Free - Free -35 60 10 Free -- Free - Free -
11 120 96 Free -107 120 107 110 9
52 126 59 120 35
93 126 93 l i s 99
40 126 73 120 15
- Free - Free -Free -- Free -
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May 27, 2015
Tabie 9: Time of Day Signal Coordination Schedule for Weekday and Weelcend Peak Periods for IVIt. Diablo Boulevard and Moraga
Road Corridor
6
7
8
9
10
11
12
Mt.Diablo Boulevard/Dolores
Drive-Mountain View Drive
Mt. Diabio Boulevard/
Happy Valley Road
Mt. Diablo Bouievard/Dewing
Avenue
Mt. Diablo Boulevard/
Lafayette Circles (West)
Mt. Diabio Boulevard/Oak
Hill Road-Lafayette Circles
(East)
Mt. Diablo Boulevard/
Moraga Road
Mt. Diablo Boulevard/
1st Street
Mt . Diablo Boulevard/
2nd Street
Mt. Diablo Boulevard/
Brown Avenue-AI ma nor Lane
Moraga Road/
Moraga Boulevard
Moraga Road/School Street-
Brook Street
Moraga Road/St. Mary's
Road- Herman Drive
7:30-9:30
7:30-9:30
7:30-9:30
7:30-9:30
7:00-9:30
7:00-9:30
7:00-9:30
7:00-9:30
7:00-9:30
100
100
100
100
120
120
120
Free
Free
120
120
Free
11:30-14:45
11:30-14:45
11:30-14:45
9:30-14:45
Free 14:45-15:45
Free 14:45-15:45
Free 14:45-15:45
Free 14:45-15:45
100 15:45-18:45 100
100 15:45-18:45 100
100 15:45-18:45 100
100 15:45-18:45 100
11:30-14:45 125 14:45-15:45 126 15:45-18:45 120
126 14:45-15:45
126 14:45-15:45
Free 14:45-15:45
Free 14:45-15:45
126 14:45-15:45
126 14:45-15:45
Free
126 15:45-18:45 120
126 15:45-18:45 120
60 15:45-18:45 60
120 15:45-18:45 120
126 15:45-18:45 126
126 15:45-18:45 126
Free Free
10:00-15:30 100
10:00-15:30 100
10:00-15:30 100
10:00-15:30 100
10:00-15:30 120
10:00-15:30 120
10:00-15:30 120
Free
Free
10:00-15:30 120
10:00-15:30 120
Free
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Deliverable #4S; Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27,2015
T iming P lan I m p l e m e n t a t i o n a n d Eva lua t ion
TJKM in col laborat ion w i t h the City s taf f in i t ia ted t h e Implementa t ion of the proposed t imings dur ing
the m o n t h of March 2015. TJKM w i th t he assistance o f t he City Staff ut i l ized QuicLoad Laptop
Sof tware which permi ts uploading and down load ing o f t ra f f ic signal t im ing parameters by connect ing
the laptop direct ly t o the t raf f ic signal contro l ler t o input the proposed t imings at each study
intersect ion. A f te r imp lementa t ion of t he proposed t imings, TJKM f ine- tuned the offsets where
needed based on in-person f ie ld observat ions of t ra f f i c condit ions opera t ing under t he revised t im ing
parameters. The f ine- tun ing of t he t im ing plans also Included dr iv ing along the s tudy corr idor ,
ident i fy ing locations where vehicles s top, and ref in ing t he offsets and splits t o improve t ra f f ic f l ow
along t h e s tudy corr idor. Fine-tuning was per fo rmed for each t raf f ic peak per iod over a number o f
weekdays and weekends. See Appendix E fo r t he revised t im ing sheets a f ter f ine- tun ing and
imp lementa t ion .
Installation of GPS clocks
To proper ly opera te t he coord inat ion t im ing on a cor r idor basis, GPS clocks w e r e Installed at all
project intersect ions t o synchronize t he t ime of t he clocks present in t he f ie ld contro l lers.
Evaluation
After t he new t im ing plans had been imp lemen ted , a new round of t rave l t ime surveys was
conducted dur ing the a.m., midday, school p.m. and p.m., and weekend peak periods t o de te rmine
the effect iveness o f the new plans along the M t . Diablo Boulevard and Moraga Road study corr idors.
The "A f te r " f loa t ing car runs fo r the study corr idors are summarized in Tables 10 ,11 and 12. Detai led
"A f te r " t ravel t i m e summary sheets are conta ined In Appendix B.
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Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27,2015
Table 10: Floating Car, Mt. Diablo Boulevard, "After" Travel Time Survey
0:32
3:51
3:10
2:27
2:20
0:36
4:03
3:58
3:33
Mt. Diablo Bouievard,
between Dolores
Drive and Brown
Avenue*
Midday^
1.01
0:00
1:28
0:47
0:52
0:53
0:00
1:34
1:41
1:33
0
3
1
1
2
0
3
3
3
23
16
19
18
16
22
15
15
12
40%
0%
39%
25%
36%
38%
0%
39%
43%
44%
EB School P.M.^
P.M.^
Weekend"
A.M."
Midday^
WB School P.M.^
P.M.^
Weekend" Notes:
^Average speed along the corridor Including stop delays, not reflective of actual speeds of vehicles while moving. ^Average number of stops made by a car from all the travel time runs collected on the study corridors including stops at red lights as well as other stops between intersections due to congestion. ^Signal Delay as percentage of travel time. "A.M. and W/eekend Peak Periods - Floating car runs between Dolores Drive and First Street. ^Midday Peak Period - Floating car runs between Oakhill Road and First Street. ^School P.M. and P.M. Peak Periods - Floating car runs between Dolores Drive and Brown Avenue. *There are nine (9) signalized intersections along this corridor.
Deliverable MB: final Project Report with Benefit/Cost Analysis, City of Lafayette
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May 27, 2015
Table 11: Floating Car, Mt. Diablo Boulevard between Dolores Drive and Lafayette Circle (West),
"After" Travel Time Survey
Mt, Diablo A.M. 0:22 1:02 1 18 35%
Boulevard, EB
School P.M. 0:18 0:58 1 20 32%
between EB P.M. 0:00 0:40 0 21 0%
Dolores Weekend 0:07 0:49 0 22 16% Drive and A.M. 0:15 0:57 1 18 26% Lafayette
WB Scliool P.M. 0:36 1:18 2 13 46%
Circle WB P.M. 0:10 0:50 1 21 20%
(West)* Weekend 0:06 0:46 0 23 13% Notes:
^Average speed along the corridor including stop delays, not reflective of actual speeds of vehicles while moving. ^Average number of stops made by a car from all the travel time runs collected on the study corridors including stops at red lights as well as other stops between intersections due to congestion. ^Signal Delay as percentage of travel time. *There are four (4) signalized Intersections along this corridor. The corridor was not coordinated for the weekday midday peak period based on analysis. Hence, floating car survey for this peak period is not provided.
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Deliverable MB: Final Project Report witii Benefit/Cost Analysis, City of Lafayette May 27,2015
Table 12: Floating Car, Moraga Road from Mt. Diablo Boulevard to St. Mary's Road, "AfteK' Travel
Time Survey
lU U t'
A M 0 2 7 1 4 1 1 17 26%
Midday 0:09 1:17 1 22 12%
NB Scliool P.M. 1:04 2:08 1 13 50%
P.M. 0:49 1:59 2 15 4 1 %
Moraga Weekend 0:57 2:04 1 13 46%
Road* A.M. 0:13 1:15 0 22 19%
Midday 0:00 1:01 0 26 0%
SB School P.M. 0:08 1:16 1 21 12%
P.M. 0:20 1:28 1 20 23%
Weekend 0:02 1:10 1 23 3% Notes:
^Average speed along the corridor Including stop delays, not reflective of actual speeds of vehicles while moving. ^Average number of stops made by a car from all the travel time runs collected on the study corridors including stops at red lights as well as other stops between intersections due to congestion. ^Signal Delay as percentage of travel time. *There are four (4) signalized intersections along this corridor.
To gauge the ef fect o f t he new t im ing plans, the "Be fo re" and "A f te r " condi t ions w e r e compared.
Tables 13 ,14 and 15 summarize the est imated measures of effectiveness (MOE) based on the
recommended t im ing plans fo r the s tudy corr idors and compares t h e m t o Existing Condit ions MOEs.
For a fa i r compar ison t o existing condi t ions and t o reflect the var iat ion in t ra f f ic character, the M t .
Diablo Boulevard cor r idor is div ided in to t w o sections - Dolores Drive t o Brown Avenue, and Dolores
Drive t o Lafayette Circle (West). The sect ion of Dolores Drive t o Lafayette Circle (West) was analyzed
separately t o prov ide a compar ison be tween exist ing condi t ions where t he intersect ions opera ted
under " f ree " condi t ion and the proposed t im ing plans. Moraga Road is t rea ted as a single corr idor.
Appendix F contains t he Synchro mode l ou tpu t results f o r t he Arter ia l Level of Service and the MOEs
f o r t h e study corr idor , and the compar ison of MOEs under "Be fo re" and "A f t e r " condi t ions. As t he
tables show, t he imp lementa t ion o f recommended signal t im ing plan has general ly resulted in
reduct ions t o signal delay per vehicle, stops per vehicle, and to ta l t ravel t i m e , as we l l as increases t o
the average speed o f t h e corr idors based on t he observat ions f r o m the "A f te r " f loat ing-car surveys.
Along var ious sub-sections tested on M t . Diablo Boulevard be tween Dolores Drive and Brown
Avenue, data showed signif icant decrease in signal delay, t rave l t ime , stops; and increase in speed
dur ing t he weekday a.m., midday, school p.m. and p.m., and weekend peak per iods in t he eastbound
and wes tbound d i rec t ion . It was observed tha t there was approx imate ly an average reduct ion of
50% in stops per vehicle along M t . Diablo Boulevard fo r all peak periods w i t h t he Implementa t ion of
the proposed t im ing plans.
Moraga Road (be tween M t . Diablo Boulevard and St. Mary 's Road-Herman Drive) also showed
signif icant decrease in signal delay, t rave l t ime , stops; and increase in speed. It was observed tha t
there was approx imate ly an average reduct ion of 50% in stops per vehicle along Moraga Road fo r all
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Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27,2015
peak periods w i t h the imp lementa t ion of the proposed t im ing plans. However, it should be noted
that Moraga Road operates under saturated t ra f f ic condi t ions dur ing most of t he peak per iods,
where t rave l speeds are in t he low teens. The reduct ion in stops helps reducing delay to a certa in
extent in the overal l t ravel t ime f r om one end of t he corr idor t o the o ther , thus producing a faster
overal l average t ravel speed. However, congest ion sti l l occurs w i t h t he revised signal t im ings, which
are no t expectted t o produce " f ree f l o w " condit ions in t ra f f ic given tha t demand fa r exceeds t he
avai lable capacity dur ing the highest peak of t he peak per iod.
General ly, t he results show benefi ts t o updat ing t he current coord inat ion t imings, and adding certain
uncoord inated Intersections t o t he system dur ing certa in t imes of day. On M t . Diablo Boulevard the
t ravel t i m e improved up t o one or t w o minutes fo r most peak periods. On Moraga Road, t he benefi ts
are much more l im i ted , however, the t ravel t i m e improved up t o one m inu te dur ing certain t imes of
day. It was observed tha t the re was an average reduct ion in stops by approx imate ly 50% fo r bo th
study corr idors and a substant ial increase in speed dur ing certain t imes of day.
During Fine-tuning and Implementa t ion o f the proposed t im ing plans and "A f te r " f loa t ing car
surveys, t he fo l low ing observat ions were made:
1. The intersect ion o f M t . Diablo Boulevard and Happy Valley Road has "cond i t i ona l " service fo r
t he eastbound left t u rn movemen t f r o m M t . Diablo Boulevard on to Happy Valley Road
dur ing "Free" opera t ion . Condit ional service al lows this movemen t t o be served tw ice in a
given cycle t o reduce the bui ld-up of queues. Due t o technological constraints w i t h i n t he
t ra f f ic contro l ler , condi t ional service is incompat ib le w i t h a coord inated p lan. It was noted
dur ing f ie ld observat ions that p.m. peak queu ing in t he eastbound d i rect ion can extend wel l
beyond the available t u rn pocket. This queuing is somewhat exacerbated in coord inated
mode o f operat ion dur ing certa in cycles. However , typical ly the new t im ing al lows the
eastbound left t u rn queue t o clear a lmost complete ly every cycle. Fur thermore , even when
the left t u rn queue spills over t o t he number one th rough lane, there is suf f ic ient capacity in
t he remain ing th rough lane t o accommodate t raf f ic w i t h o u t signif icant delay.
2. On the M t . Diablo Boulevard corr idor , several intersect ions are proposed t o be added t o the
coord inated system fo r certa in t imes o f day. It was expected t ha t t he new coord inated
t im ing wi l i provide Improved condi t ions along the main l ine bu t minor movements w i t h i n an
intersect ion w o u l d degrade sl ightly. TJKM's f ie ld observat ions no ted t ha t t he intersect ions o f
Dolores Drive, Happy Valley Road, Dewing Avenue and Lafayette Circle (V\/est) are no t
signif icantly impacted due t o t h e proposed coord inat ion plans dur ing f ine- tun ing and
imp lementa t ion . A compar is ion o f "Be fo re" and "A f te r " f loat ing car surveys reflects t ha t t he
coord inat ion benefi ts the corr idor overal l .
3. There are existing pedestr ian crosswalks crossing mainl ine t ra f f ic at t he intersect ion of M t .
Diablo Boulevard and Golden Gate Way. Heavy pedestr ian act iv i ty was observed at th is
intersect ion dur ing t he weekday p.m. peak per iod. TJKM observed this intersect ion dur ing
t he imp lementa t ion and f ine- tun ing phase t o assess if vehicular progression is impacted by
t he pedestr ian act iv i ty, and if the proposed coord inat ion w i l l have any adverse ef fect on the
safety and mobi l i ty o f pedestr ians. It was no ted t ha t coord inat ion dur ing p.m. peak per iod
was no t hampered due t o the pedestr ian t ra f f ic , and no pedestr ian safety issues w e r e noted
dur ing f ie ld observat ions.
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Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27, 2015
4. The in tersect ion of M t . Diablo Boulevard and Moraga Road experiences heavy wes tbound
left t u rn t ra f f ic on to Moraga Road at var ious t imes. This movemen t has been coord inated
w i t h the southbound th rough movemen t along the Moraga Road corr idor t o prov ide
cont inuous progression. It was noted t ha t t he ent i re queue col lected fo r t he wes tbound left
movemen t on M t . Diablo Bouievard was able t o be served wi th in t he green t i m e al locat ion of
one signal cycle, and the t ra f f ic d id not have t o s top at any intersections a long Moraga Road.
5. Another p rob lem noted before imp lementa t ion was the large percentage of no r thbound
right t u rn ing t raf f ic at the M t . Diablo Boulevard and Moraga Road intersect ion t ha t cont inues
on to M t . Diablo Boulevard t o mal<e a left at First Street. This resulted in heavy queuing fo r
t he eastbound left tu rn at First Street. This queuing extends back t o the M t . Diablo Boulevard
and Moraga Road intersect ion and blocks eastbound th rough t ra f f ic heading t o w a r d First
Street. The coordinat ion plans were developed and f ine- tuned such t ha t t he nor thbound
right tu rn ing vehicles f r om Moraga Road heading towards First Street t o make the eastbound
lef t w o u l d get served as soon as they reached First Street. This reduced queu ing and spi l lover
f r o m First Street back t o Moraga Road along M t . Diablo Boulevard.
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Deliverable mB: Fmal Project Report with Benefit/Cost Analysis, City of Lafayette May 27,2015
Table 13: "Before" and "After" Comparison of System Measures of
A.M
EB
Midday
WB
EB
Scliool
P.M.
WB
EB
P.M.
WB
EB
Weel<end WB
EB
WB
Mt. Diablo
Boulevard,
between Dolores Drive and Brown
Avenue
Existing 1:05 2:49
Proposed 1:01 2:30
% Change -6% - 1 1 %
Existing 1:29 3:21
Proposed 0:54 2:21
% Change -39% -30%
Existing 1:07 1:45
Proposed 0:00 0:32
% Change -100% -70%
Existing 1:02 1:41
Proposed 0:00 0:36
% Change -100% -64%
Existing 2:37 5:41
Proposed 1:28 3:51
% Change -44% -32%
Existing 3:19 6:26
Proposed 1:34 4:03
% Change -53% -37%
Existing 3:07 5:56
Proposed 0:47 3:10
% Change -75% -47%
Existing 3:45 6:22
Proposed 1:41 3:58
% Change -55% -38%
Existing 1:27 3:38
Proposed 0:52 2:27
% Change -40% -33%
Existing 1:58 4:02
Proposed 1:33 3:33
% Change - 2 1 % -12%
Deliverable ff4B: Final Project Report with Benefit/Cost Analysis, City of Lafayette
(MOEs) for Mt. Diablo Boulevard
2 3.07 0.6 15
2 2.44 0.47 16
0% - 2 1 % -22% 7%
3 3.75 0.73 11
2 3.25 0.63 16
-33% -13% -14% 45%
1 2.04 0.4 9
0 1.72 0.34 23
-100% -16% -15% 156%
1 1.53 0.3 8
0 1.44 0.28 22
-100% -6% -7% 175%
5 6.56 1.28 10
3 6.02 1.17 16
-40% -8% -9% 60%
6 4.76 0.93 9
3 4.6 0.89 15
-50% -3% -4% 67%
4 7.18 1.4 10
1 6.69 1.3 19
-75% -7% -7% 90%
4 4.85 0.94 9
3 4.44 0.85 15
-25% -8% -9% 67%
3 4.56 0.89 11 1 3.84 0.75 18
-67% -16% -16% 64%
3 3.69 0.72 10
3 3.26 0.63 12
0% -12% -13% 20%
Page 27
May 27, 2015
Table 14:"Before" and "After" Comparison of System IVIeasures of Effectiveness (MOEs) for Mt. Diablo Boulevard, between Dolores
Drive and Lafayette Circle (West)
Mt. Diablo Boulevard,
between Dolores Drive and
Lafayette Circle
(West)
A.M.
School
P.M.
P.M.
V\/eekend
1 1.15 14 EB Proposed 0:22 1:02 1 0.86 0.17 18
% Change -27% -17% 0% -25% -23% 29% Existing 0:34 1:25 2 1.77 0.34 12
WB Proposed 0:15 0:57 1 1.50 0.29 18
% Change -56% -33% -50% -15% -15% 50% Existing 0:38 1:34 2 1.77 0.35 11
EB Proposed 0:13 0:58 1 1.27 0.25 20
% Change -53% -38% . -50%. -28% -29% 82%
Existing 0:39 1:45 1 1.54 0.30 12
WB Proposed 0:36 1:18 2 1.35 0.26 13
% Change -S% -26% 100% -12% -13% 8%
Existing 0:51 1:44 1 2.30 0.45 10
EB Proposed 0:00 0:40 0 1.56 0.30 21 % Change -100% -62% -100% -32% -33% 110%
Existing 1:32 2:22 2 1.67 0.33 a
WB Proposed 0:10 0:50 1 1.59 0.31 21
% Change -89% -65% -50% -5% -6% 163%
Existing 0:30 1:25 1 1.84 0.36 13
EB Proposed 0:07 0:49 0 1.34 0.26 22
% Change -77% -42% -100% -27% -28% 69%
Existing 0:18 1:15 1 1.35 0.26 16
WB Proposed 0:06 0:46 0 1.15 0.22 23
% Change -67% -39% -100% -15% -15% 44%
Deliverable #4S; f /no/ Project Report with Benefit/Cost Analysis, City of Lafayette
Page 28
May 27, 2015
TJKM Transportation
Consultants
Table 15: "Before" and "After" Comparison of System IVIeasures of Effectiveness (MOEs) for Moraga Road
A.M.
Midday
Moraga Road School P.M.
P.M.
Weekend
Existing 1:43 2:54 2 3.73 0.73 10 NB Proposed 0:27 1:41 1 3.37 0.66 17
% Change -74% -42% -50% -10% -10% 70%
Existing 0:14 1:28 1 2.10 0.41 IS SB Proposed 0:13 1:15 0 2.12 0.41 22
% Change -7% 40% -100% 1 % 0% 22%
Existing 1:48 2:54 2 2.83 0.55 9
NB Proposed 0:09 1:17 1 2.84 0.55 22
% Change -92% -56% -50% 0% 0% 144%
Existing 0:21 1:28 1 2.21 0.43 IS
SB Proposed 0:00 1:01 0 2.11 0.41 26
% Change -100% - 3 1 % -100% -5% -5% 44%
Existing 2:12 3:02 2 3.32 0.64 12
NB Proposed 1:04 2:08 1 3.30 0.64 13
% Change -52% -30% -50% - 1 % 0% 8%
Existing 1:35 3:10 2 2.75 0.53 9
SB Proposed 0:08 1:16 1 2.64 0.51 21
% Change -92% -60% -50% -4% -4% 133%
Existing 0:43 1:52 2 2.98 0.58 14
NB Proposed 0:49 1:59 2 2.76 0.54 15
% Change 14% 6% 0% -7% -7% 7%
Existing 0:35 1:39 1 3.32 0.65 16
SB Proposed 0:20 1:28 1 3.25 0.63 20
% Change -43% - 1 1 % 0% -2% -3% 25%
Existing 1:12 2:22 2 3.04 0.59 11
NB Proposed 0:57 2:05 1 3.23 0.63 13
% Change - 2 1 % -12% -50% 6% 7% 18%
Existing 0:13 1:15 2 2.42 0.47 21
SB Proposed 0:03 1:10 1 2.38 0.46 23
% Change -77% -7% -50% -2% -2% 10%
Deliverable U4B: Final Project Report witti Benefit/Cost Analysis, City of Lafayette
Page 29
May 27, 2015
TJKM Transpor-tation
Consultants
B e n e f i t / C o s t Rat io A n a l y s i s
As stated previously, th is study is funded by the IVIetropolitan Transportat ion Commission (MTC). As part
o f the be fo re /a f te r compar ison, IViTC requires a benef i t /cost analysis t o de te rmine t h e amoun t of
theoret ica l public benef i t der ived f r o m invest ing in the Program f o r Arterial System Synchronizat ion
(PASS). The benef i t /cost analysis also accounts fo r improvement in t raf f ic operat ion fo r autos and safety
f o r pedestr ians and bicyclists.
A summary of some Itey f indings f r om the results of the benef i t -cost analysis is as fo l lows :
• Average reduct ion in t ravel t ime - 35%
• Average speed increase - 62%
• Average fuel savings - 24%
• Average reduct ion in stops - 4 5 %
• The results o f t he analysis showed a to ta l 5-year l i fe t ime travel t ime savings o f approx imate ly
$4,401,363 and fuel consumpt ion savings o f approx imate ly $58,810
• Total cost of t h e projects including the consul tant cost and agency staf f costs is approx imate ly
$98,960 for deve lopment and imp lementa t ion o f t he coord inat ion plans
• The project obta ined a benef i t /cost rat io of nearly 48 :1
Table 16 summarizes t he results of t he measures o f effect iveness and benef i t /cost analysis conducted fo r
t he s tudy corr idor. As indicated under each of the "Be fo re" vs. "A f te r " condi t ions tables, it was observed
tha t there was a signif icant improvement in t raf f ic signal coord inat ion and t ravel t ime reduct ion along
t he study corr idor. The project is expected t o result in a signif icant reduct ion in greenhouse
gases/harmful emissions. Append ix G contains a deta i led spreadsheet fo r t he benef i t /cost analysis w i t h
all t he assumptions t ha t were considered In t he analysis. The methodo logy and assumptions used In
est imat ing t he var ious publ ic benefits are consistent w i t h those accepted by MTC in evaluat ing s imi lar
projects under t he PASS program.
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Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette May 27, 2015
Table 16: Benefit /Cost Analysis
Costs
Consultant Costs {Basic Services/Plans) $70,800
Consultant Costs (Additional Plans, TSP, IM Flush Plans, etc.) $6,500
Other Project Costs {GPS Clocks, Communications equipment, etc.) $3,960
Agency Staff Costs (Local agency, MTC, Caltrans, etc,)^ $17,700
Total Costs $98,960
Benefits
Measures First Year Lifetime (5 Yearsf
Measures Savings Monetized Savings Savings Monetized Savings
Travel Time Savings (hrs) 84,074 $1,640,735 225,533 $4,401,363
Fuel Consumption Savings (gal) 5,681 $21,923 15,239 $58,810
ROG Emissions Reduction (tons) 0.02 $28 0.06 $76
NOx Emissions Reduction (tons) 0.01 $244 0.04 $656
PM2.5X Emissions Reduction (tons) 0.00 $235 0.00 $630
CO Emissions Reduction (tons) 0.15 $12 0.41 $32
Total Lifetime Benefits $4,461,567
Overall Project Benefits Auto
Average Decrease in Travel Time 35%
Average Speed Increase 62%
Average Fuel Savings 24%
Benefit/Cost Ratio 48:1
Notes:
1. General methodology, fuel consumption factors, and health costs of motor vehicle emissions based on Califomia Department of
Transportation, Office of Transportation Economics. California Life-Cycle Benefit/Cost Analysis Model and Technical Supplement to the
User's Guide, 2009
2. Benefits claimed include travel time savings, fuel consumption savings, and health cost savings associated with emissions reductions for
the coordinated pealc periods indicated above. Yearly savings calculated based on 250 daysof worltdaysin a year. 3. Value of time
assumed to be 50 percent of the wage rate for off-the-clock travel or $19.52 in 2013 constant dollars. Bay Area average wage rate is
$20,82 per hour in 1990 constant dollars, based on Travel Demand l\/lodeis for the San Francisco Bay Area [BAYCAST-90] Technical
Summary, Table A, p. 28, June 1997. Adjusted for inflation using CPI, from US Dept of Labor, Bureau of Labor Statistics, CPI - AH Urban
Consumers, San l^rancisco-Oakland-San Jose, CA area. All Items, Not Seasonally Adjusted (Series ld:CUURA422SA0), Vehicle fleet assumed
to be 100 percent automobiles.
4, Average vehicle occupancy assumed to be 1.118 persons per vehicle and is used in calculating travel-time savings In autos only. This is
based on the San Francisco Bay Area Baycast Travel Model run for the RTP 2009 (using the 2010 network) developed by the Metropolitan
Transportation Commission.
5, Average fuel cost is from US Dept of Labor Bureau of Labor Statistics, CPI - Average Price Data, San Franclsco-Oakland-San Jose, CA area.
Gasoline unleaded regular per gallon. Average of monthly prices in the Ba^^Area from January 2013 -December 2013 Is $3,859.
6, Health cost of ROG Emissions ($1,259 per ton), NOx Emissions ($17,997 per ton), and CO Emissions ($77 per ton) are based on the
Cailfornia Department of Transportation, Office of Transportation Economics from Exhibit 111-43, p. 111-69 of the California Life-Cycle
Benefit/Cost Analysis Model Volume 3 Technical Supplement to User's Guide, Revision 2 (February 2012). The 2013 costs are calculated
with a standard assumption of 2% increase per year from the 2011 costs. PM2.5x Emissions {$312,351 per ton) costs, are based on
Victoria Transport Policy Institute's Air Pollution Costs, with 2013 costs calculated with a standard assumption of 2% increase per year
from 2007 costs.
Deliverable MB: Final Project Report with Benefit/Cost Analysis, City of Lafayette
Page 31
May 27,2015
7. Project life assumed to be five years. Benefits assumed to be 100 percent on first day after implementation, declining steadliy to zero by
end of the fourth year. Benefits equivalent to sum of discounted average annuai benefits, where averages are 90% of First Year for year 0,
70% for year 1,50% for year 2, 30% for year 3, and 10% for year 4.
8. Ali public agencies involved staff costs assumed to be 25% of the project consultant costs.
Benefits to Otiier Modes
Addi t ional ly , the PASS project in Lafayette provided an oppo r tun i t y t o update t ra f f ic signal t im ing
parameters f o r consistency w i t h establ ished guidelines as follow/s:
Traffic Safety Benefit
To enhance t ra f f ic safety, t he ye l low clearance t im ing parameters were conf i rmed or updated based on
posted speed l imits a long the s tudy corr idor.
Benefits to Pedestrians
The "Wa lk " t im ing and "Flash Don ' t Wa lk " clearance t im ing parameters were also upda ted t o provide
adequate t i m e fo r pedestr ians to safely cross the intersect ions, based on the new walk ing speed of 3.5
fee t /second, as specif ied in 2012 California MUTCD standards.
Benefits to Bicyclists
For improved bike safety, the m in imum green intervals were updated t o ensure tha t bicyclists can clear
t he intersections.
Conclusion
The traf f ic signal coord inat ion plans are expected t o improve t ra f f ic progression and p romo te un i fo rm
t rave l speeds along t h e study corr idor thus reducing dr iver f rus t ra t ion . Imp lementa t ion o f t he t im ing
plans has resul ted in reduct ion in t ra f f ic delay and automobi le t rave l t ime , a l lowing reduct ion in harmfu l
greenhouse gas emissions. Other benef i ts include improvements t o pedestr ian and bicycle mobi l i ty in
te rms of updated signal t im ing accommodat ion consistent w i t h current standards and guidel ines.
Deliverable #46; Final Project Report with Benefit/Cost Analysis, City of Lafayette
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May 27, 2015
G l o s s a r y
Actuated Signal
An Actuated Signal uses vetiicle detectors t o vary pliase t im ing according t o demand.
Actuated Coord ina ted
In an Ac tua ted Coordinated system, t t ie minor movemen t phases are actuated and the major - road
th rough movemen t phases are non-actuated. The contro l ler 's force-of f sett ings are used t o ensure tha t
the non-actuated phases are served at t he appropr ia te t i m e dur ing the signal cycle such tha t progression
f o r t h e major- road th rough movement is main ta ined.
Ac tua ted Uncoord ina ted
In this t ype of system, the cycle length is a l lowed t o vary each cycle based on de tec t ion . The cycle length
constraint is removed in an Actuated Uncoord inated system especially dur ing oversaturated per iod t o
provide ef fect ive real locat ion of green t ime , provided the gap t imers are set accurately. This provides
green t i m e based on vehicle demand w i t h all served phases ful ly actuated and no recalls set. Traff ic f l ow
is contro l led w i t hou t consider ing t he operat ion o f adjacent t raf f ic signals.
All Red
All Red is the interval dur ing wh ich alt phases receive a red indicat ion. The purpose of t he all red interval
is t o a l low vehicles t ha t entered t he intersect ion dur ing t he yel low interval t o clear t he intersect ion
before a green indicat ion is given t o a conf l ic t ing movemen t .
Coord ina ted Opera t i on
It Is a mode o f operat ion whereby t he phase sequencing and t im ing at one signal is synchronized w i t h
those of adjacent signals in order t o enhance t raf f ic f l o w th rough the system.
Cycle Length
Cycle Length is the t i m e required fo r a comple te sequence o f phases at a signal. It is typical ly measured
as t he t ime elapsed f r o m the end of main s t reet green t o t he end of main s t reet green again. Cycle length
remains constant w i t h f ixed t i m e signals but varies f r o m cycle t o cycle w i t h actuated signals.
Lane Ut i l i za t ion
The Lane Uti l izat ion Factor determines h o w the t ra f f ic vo lumes assigned t o a lane group are d is t r ibuted
across each lane. A value o f one (1) indicates equal d is t r ibu t ion across all lanes. A value less t han one
lower 's the saturat ion f l o w rate because all lanes are not wo rk ing at fu l l capacity.
Minimum Gap Time
It is the m in imum value t o wh ich a passage t ime can be reduced by the gap reduct ion func t ion .
Minimum Initial
M i n i m u m Init ial is a vo lume density set t ing. It is t he m i n i m u m dura t ion o f green tha t must be displayed
f o r a given phase.
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TJKM Transporcition
Consultants
Offset
The of fset f o r a signalized intersect ion is def ined as t he t ime d i f ference between the intersect ion
reference point and t ha t of the system master. The Intersect ion reference point is typical ly specif ied t o
occur at t h e planned start (or end) of t he green interval fo r t he f i rs t coord inated phase. The " f i rst
coord inated phase" is t he coord inated phase tha t occurs f i rst (of all coord inated phases) fo r a given
phase sequence and splits.
Pedestrian Clearance Interval/Flashing Don't Walk
Interval dur ing which pedestr ians w h o have already entered t he crosswalk are a l lowed t o comple te the i r
crossing. If pedestr ian heads are prov ided, this is t he 'Flashing Don' t Walk ' interval . If pedestr ian heads
are not prov ided, this is a por t ion of t he vehicle green phase.
Split Phasing:
Split phasing represents an assignment o f t he r ight -of -way t o all movements of a par t icu lar approach,
fo l lowed by all o f t he movements of the opposing approach. Split phasing may be necessary when
intersect ion geomet ry results in partial ly conf l ic t ing vehicle paths th rough the intersect ions or whe re the
approaches are of fset such tha t opposing left tu rn ing vehicles w o u l d have t o occupy t he same space t o
comple te the i r turns. If the intersect ion has high lef t t u rn and t h rough vo lume, t he t ra f f ic engineer may
have t o use shared lef t t u rn and th rough lanes t o make ef f ic ient use o f the approach wh ich w o u i d also
result in spl i t phasing fo r t he approach.
Vehicle Extension (Passage time)
The amoun t of t ime , t he green interval is extended fo r a vehicle actuat ion. If t he cont ro l le r receives
another vehicle actuat ion before t he passage t ime has expi red, t he passage t imer w i l l be reset to t he
passage t i m e . The passage t ime is p rogrammed in t he cont ro l le r and typical ly ranges f r o m 2.0 sec. t o 6.0
sec.
Walk Interval
Interval dur ing which pedestr ians wa i t ing on t he curb may enter t he crosswalk and begin a crossing.
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