Consider the geometric and traffic characteristics shown below. Approach (Width) Peak hour Approach Volumes: Left Turn Through Movement Right Turn Conflicting Pedestrian Volumes PHF For the following saturation flows: North (56 ft) South (56 ft) East (68 ft) West (68 ft) 165 105 200 166 442 395 585 538 162 157 191 200 900 1,200 1,200 900 0.95 0.95 0.95 0.95 Through lanes: 1,600 veh/h/in Through-right lanes: 1,400 veh/h/in Left lanes: 1,000 veh/h/in Left-through lanes: 1,200 veh/h/in Left-through-right lanes: 1,100 veh/h/in The total cycle length was 277 s. Now assume the saturation flow rates are 10% higher, that is, assume the following saturation flow rates: Through lanes: Through-right lanes: Left lanes: Left-through lanes: Left-through-right lanes: 1,760 veh/h/in 1,540 veh/h/in 1,100 veh/h/in 1,320 veh/h/in 1,210 veh/h/in Determine a suitable signal phasing system and phase lengths (in s) for the intersection using the Webster method. (Enter the sum of green and yellow times for each phase, and afterwards the total cycle length. Ensure that enough green time is provided to allow for pedestrian movement. Assume each of the four approaches is divided into a left lane, a through lane, and a through-right lane. Assume the lost time due to acceleration and deceleration during each phase is 3.5 seconds, and the time lost due to the red dearance interval between each phase is 1.5 seconds. Also, assume the curb-to-curb distance is 56 ft when pedestrians travel during the N-S phases and 68 ft when pedestrians travel during the E-W phases. Finally, assume pedestrians walk at a speed of 3.5 ft/s through a crosswalk of width 10 ft.) Phase 1: N-S left turn Phase 2: N-S through & through-right tum Phase 3: E-W left turn Phase 4: E-W through & through-right turn Total cycle length 5 S What effect does the increase in saturation flow rates have on cycle length? By increasing saturation flow rates by 10%, the recommended total cyde length -Select-- ' %.
Consider the geometric and traffic characteristics shown below. Approach (Width) Peak hour Approach Volumes: Left Turn Through Movement Right Turn Conflicting Pedestrian Volumes PHF For the following saturation flows: North (56 ft) South (56 ft) East (68 ft) West (68 ft) 165 105 200 166 442 395 585 538 162 157 191 200 900 1,200 1,200 900 0.95 0.95 0.95 0.95 Through lanes: 1,600 veh/h/in Through-right lanes: 1,400 veh/h/in Left lanes: 1,000 veh/h/in Left-through lanes: 1,200 veh/h/in Left-through-right lanes: 1,100 veh/h/in The total cycle length was 277 s. Now assume the saturation flow rates are 10% higher, that is, assume the following saturation flow rates: Through lanes: Through-right lanes: Left lanes: Left-through lanes: Left-through-right lanes: 1,760 veh/h/in 1,540 veh/h/in 1,100 veh/h/in 1,320 veh/h/in 1,210 veh/h/in Determine a suitable signal phasing system and phase lengths (in s) for the intersection using the Webster method. (Enter the sum of green and yellow times for each phase, and afterwards the total cycle length. Ensure that enough green time is provided to allow for pedestrian movement. Assume each of the four approaches is divided into a left lane, a through lane, and a through-right lane. Assume the lost time due to acceleration and deceleration during each phase is 3.5 seconds, and the time lost due to the red dearance interval between each phase is 1.5 seconds. Also, assume the curb-to-curb distance is 56 ft when pedestrians travel during the N-S phases and 68 ft when pedestrians travel during the E-W phases. Finally, assume pedestrians walk at a speed of 3.5 ft/s through a crosswalk of width 10 ft.) Phase 1: N-S left turn Phase 2: N-S through & through-right tum Phase 3: E-W left turn Phase 4: E-W through & through-right turn Total cycle length 5 S What effect does the increase in saturation flow rates have on cycle length? By increasing saturation flow rates by 10%, the recommended total cyde length -Select-- ' %.
Traffic and Highway Engineering
5th Edition
ISBN:9781305156241
Author:Garber, Nicholas J.
Publisher:Garber, Nicholas J.
Chapter8: Intersection Control
Section: Chapter Questions
Problem 8P
Related questions
Question
Transcribed Image Text:Consider the geometric and traffic characteristics shown below.
Approach
(Width)
Peak hour Approach Volumes:
Left Turn
Through Movement
Right Turn
Conflicting Pedestrian Volumes
PHF
For the following saturation flows:
North
(56 ft)
South
(56 ft)
East
(68 ft)
West
(68 ft)
165
105
200
166
442
395
585
538
162
157
191
200
900
1,200
1,200
900
0.95
0.95
0.95
0.95
Through lanes:
1,600 veh/h/in
Through-right lanes:
1,400 veh/h/in
Left lanes:
1,000 veh/h/in
Left-through lanes:
1,200 veh/h/in
Left-through-right lanes:
1,100 veh/h/in
The total cycle length was 277 s. Now assume the saturation flow rates are 10% higher, that is, assume the following saturation flow rates:
Through lanes:
Through-right lanes:
Left lanes:
Left-through lanes:
Left-through-right lanes:
1,760 veh/h/in
1,540 veh/h/in
1,100 veh/h/in
1,320 veh/h/in
1,210 veh/h/in
Determine a suitable signal phasing system and phase lengths (in s) for the intersection using the Webster method. (Enter the sum of green and yellow times for each phase, and afterwards the total cycle length. Ensure that enough green time is provided to allow for pedestrian movement. Assume each of the four approaches is divided into a left lane, a through lane, and a through-right lane. Assume the lost time due to acceleration and deceleration during each phase is 3.5 seconds, and the time lost due to the red dearance interval between each phase
is 1.5 seconds. Also, assume the curb-to-curb distance is 56 ft when pedestrians travel during the N-S phases and 68 ft when pedestrians travel during the E-W phases. Finally, assume pedestrians walk at a speed of 3.5 ft/s through a crosswalk of width 10 ft.)
Phase 1: N-S left turn
Phase 2: N-S through & through-right tum
Phase 3: E-W left turn
Phase 4: E-W through & through-right turn
Total cycle length
5
S
What effect does the increase in saturation flow rates have on cycle length?
By increasing saturation flow rates by 10%, the recommended total cyde length -Select-- '
%.
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