HomeMy WebLinkAboutWS Item 01 - Signal Retimingity of rapevine
Traff'ic S"ignal
Reti i ng
Workshop
2/17/2004
0
Traffic Signals in Grapevine
N
2/17/2004
MEN
Signal Ti ing Concepts
■What is signal timing: setting green, yellow and all -red times for each
movement. Signal timing is a function of
■traffic volumes (amount and direction)
■# of lanes
■Pre -timed Vs Actuated Signals
■Cycle Length (Time required to service all movements)
•Free Operation: Signal timing is optimized for individual signal
■Min.
Green,
Max Green,
Yellow & All Red. Times
■Max.
Green
varies by #
of actuations
■Cycle length varies
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■ What is signal coordination?
a
■ create a link (in time and space) between the signals on a street so
that vehicles can travel through the arterial with minimum stops.
■ Focus is on the predominant traffic flow
■ Objective:
■ to minimize Stops (especially in predominant travel direction)
■ Improve travel times (especially in predominant travel direction)
■ Reduce pollution
• improve traffic safety
■ Nationwide, average delay improvement is about 10%
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Signal Coordination - Typical Steps
I Collect data on traffic vo'lumes, lane configuration,
speeds, storage lengths, signal phasing etc.
I Determine peak periods — decide on # of timing plans
I Use an optimization software to come up with signal
timings for each period.
I Use simulation software to check for problems
I Transfer the timings to the controllers
I Fine tune on the field
I Make adjustments and repeat the process until we get it
rig ht
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Signal Coordination Concepts
• Signal •d -by time -of -day based on +
volume patterns. Typical patterns are from
• i 9:00 a
•!1 4:00 p
!i • 11 •
Free operation during other times
• Cycle length has to be same for all -signals on a street
• Unused time for other movements goes to major street
• The major street green begins (or ends) at the same
timi •ach cycle.
other• The main street green beginning (or end) times are
offset a specific time from the main street green of
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60 Second Length
30� �4
il
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4500
4000
3500
1M
2500
a�
;_
0
> 2000
1500
We
500
Traffic Volume Patterns Over a 24 Hour Period on SH 26 (Both Directions)
pp pp pp pp pp pp pp pp pp pp pp pp pp pp .pp Op Op Op .pp .pp Op Op .Op Op
0. N. �. ,�. �. ¢j. �, A 00. Cb. gyp. ^�. ��. �n�. ��. �<j• ^O. �,�. ^g• �o� gyp• �^. ��. �p.
Time
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Signal Coordination Concepts (contow)
Time-Space
.f Diagram
Main Street Time -Space Diagram Seconds
Cross Street Approach 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400
OffsetI .... I .... I..iiI.... I .... I .... I .... I .... I .... i .... I .... I .... I .... Ii...l.... I .... l .... I.... I.i.. I... d.... I.... I.... I.... h... I„.. i„i. l.... h ... I.... h ... I .... I .... I .... I .„. I .... I .... I ... i,.,. I.... I.... I"
SH 26
8
0,114 wb
�J
13
SH 26
tC
8
@ 114 EB
137
SH 26
8
@ Ernest Dean
107
SH 26
@ Heritage
7J
8
49
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NI IXN. i
I"rial
/AVE "%a
5
/ 1lJ
/ SW Arte al Band 37
NE Art4i�l Band 35
3W Arterial Band 37 s
NE Arterial Band 35 s
• „r • • • •6:.1 -
Focus is on predominant travel direction—so minor street delay at
some intersections increases.
Low volume movements typically wait longer. Longer the cycle
length, longer the wait.
Timing patterns can extend to low volume periods ( e.g. S. Main St)
Does not work well if traffic flow is interrupted by external sources,
i.e., mid block pedestrian crossings, railroad pre-emption, lane
blockages etc. (e.g. Main St)
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&su 4. 1 AWN I 1 ■ - /'y — m —1 — - - —
Km_
Signal Ti ing In Grapevine
* Streets With New Signal Timing
State ! • • (Pool •.• to Baylor)
Main Street (SH 114 to NW Hwy)
Ball " • '(Mustang to
NW Hwy)
NorthwestHighway wto Bass •
Grapevine Mills Parkway/ FM 2499 (Mail Signals)
SH 121 ( GVM Blvd & Freeport)
* The foll.owing timing plans have been implemented
AM,, Noon,, Midday, PM plans on SH 26
Midday, PM plansall other streets
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Travel Ti e I prove ents
id day peak)
State Highway 26*
4
min 14
sec
4
min 10 sec
1%
Northwest Highway
6
min 33
sec
4
min 40 sec
29%
Main Street 4 min 10 sec 3 min 45 sec 10%
WD Tate/ Ball Street 4 min 23 sec 3 min 58 sec 10%
AVERAGE IMPROVEMENT 13%
* SH 26 before travel time study conducted before Walmart Opening
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LM I - 10 1:40L41 mbbl 110 10 C
* SH 26 before travel time study conducted before Walmart Opening
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%
change
State Highway 26*
Northwest Highway
Main Street
MITI 101111 F. I tam 00109 11 W1
AVERAGE IMPROVEMENT
* SH 26 before travel time study conducted before Walmart Opening
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Signal Coordination
Co only Asked Questions
D! it mean I don't. to stop anywhere?
? Why am I waiting longer on side streets?
?Main St & Vine St
?NW Hwy & Dooley
? Sometimes there is no one on the major street and
I have towait forever on • e
? Signal coordination only helps people that are
Iriving through the City. It does not help residents.
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• Signal •• ! . • on •ll Johnson Road
• !' signals on Bass Pro Drive and Mail signals(on SH •
to coordination
Create! plans foroff-peak periods !weekends
®Establish traffic data collection system to fine tune timing
patterns and create new ones for off-peak hours.
■Camera systems to monitor traffic flow
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