The table below shows the design flow rate and saturation flow rate for a major intersection on a highway. Using the Webster method, determine the optimum cycle length for the intersection and also determine the green time for each phase. Design Flow Rate (pcu/hr) Through Saturation Flow Rate (pcu/hr) Through Phase Intergreen period (sec) Left Left 976 234 3700 1615 3.5 B. 676 135 3700 1615 3.5 C 194 26 3700 1615 3.5 322 371 3700 1615 3.5

The table below shows the design flow rate and saturation flow rate for a major intersection on a highway. Using the Webster method, determine the optimum cycle length for the intersection and also determine the green time for each phase. Design Flow Rate (pcu/hr) Through Saturation Flow Rate (pcu/hr) Through Phase Intergreen period (sec) Left Left 976 234 3700 1615 3.5 B. 676 135 3700 1615 3.5 C 194 26 3700 1615 3.5 322 371 3700 1615 3.5

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter10: Capacity And Level Of Service At Signalized Intersections

Section: Chapter Questions

Problem 4P

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An intersection has a three-phase signal with the movements allowed in each phase and corresponding analysis and saturation flow rates shown in the table below. Assume the lost time is 4 seconds per phase and a critical intersection v/c of 0.90 is desired. Phase 3 Allowed movements NB L, SB L NB T/R, SB T/R EB L, WB L ЕВ TR, WB TR Analy sis flow rate 330, 365 veh/h 1125, 1075 veh/h 110, 80 veb/h 250, 285 veh/h Saturation flow rate 1700, 1750 veh/h 3400, 3300 veh/h 650, 600 veh/h 1750, 1800 veh/h Calculate the sum of the flow ratios for the critical lane groups. 0.787 O 0.857 O 0.709 O 0,829
For the geometric characteristics, traffic conditions (traffic volumes are in vehicles per hour) and signal timing shown below, complete parts A through E for the Northbound and Eastbound approaches. A. Adjust the volumes. B. Find the saturation flow rate. C. Find the degree of saturation. D. Find the theoretical delay for each movement. E. Find the theoretical delay and LOS for the EB and NB approaches. Bus stop 5 stops/hr $12 ft teach 6% HV 400 6% HV 650 100 12 ft each - Isolated signal with random arrivals, AT-3 - No residual demand delay 11 ft each - No bicycles or pedestrians Bus stop 5 stops/hr P C = 60 sec Lost time = 3.5 sec/ 7550 2% HV - G=42 Y=4 G=10; Y=4 G=8 Y=4 G=30 Y=4 Φ1 Φ2 ФЗ Assume the intersection is located at Central Business District (CBD) Assume that both the streets are located on level grades, i.e. G = 0 Assume a PHF = 0.95 Assume random arrival i.e. AT-3 Assume that the intersection is isolated and signal is pre-timed
QUESTION 1 The approaches of a 4-leg signalized intersection are configured with 1 NB lane, 1 SB lane, 1 EB lane, and 1 WB lane and each of these lanes serves LT, TH, and RT movements. The following volumes and phasing are provided. approach EB WB NB SB movement LT TH RT LT TH RT LT TH RT LT TH RT volume 120 480 160 80 560 100 20 200 40 12 160 48 2 6 What is the critical sum for the EB/WB barrier?
A given movement at signalized intersection receives 28-seconds green time, 3.5 seconds of yellow time out of 60 seconds cycle. If saturation flow rate is 3750 vph/lane and the startup lost time is 1.5 seconds, what is the capacity of the movement? 8036 4083 1680 1750
An intersection has a three-phase signal with the movements allowed in each phase and corresponding analysis and saturation flow rates shown in the table below. Assume the lost time is 4 seconds per phase and a critical intersection v/c of 0.90 is desired. Phase 3 Allowed movements NB L, SB L NB T/R, SB T/R EB L, WB L EB TR, WB TR Analysis flow rate 330, 365 veh/h 1125, 1075 veh/h 110, 80 veh/h 250, 285 veh/h Saturation flow rate 1700, 1750 veh/h 3400, 3300 vehh 650, 600 veh/h 1750, 1 800 veh/h Using v/c equalization ratio, calculate the effective green time for phase 3 14.825 sec 15.552 sec O 11.462 sec O 16.065 sec
6. (a) Define the peak hour factor (PHF) (b) Explain the traffic condition when PHF=1. 7. The following table shows traffic flow data collected at the main road in an urban area, in two successive days during the peak period Day one Day two Time Flow (veh) Flow (veh) 7:30 – 7:45 900 7:45 – 8:00 950 960 8:00 – 8:15 1010 1015 8:15 – 8:30 990 980 (a) Determine the peak hour factor (PHF) (b) Estimate the missing traffic flow count (x) on day two.
Q1/ Use the following speed data collected from 2-lanes freeway section of 0.5 km under free- flow conditions, determine: 1- density, 2-space headway, 3- time mean speed, 4- space mean speed, 5- standard deviation, 6-variance. Speed, kph Frequency 36-40 8 41-45 10 46-50 51-55 56-60 61-65 14 22 17 11 66-70 71-75 12 4 76-80 2
4. When the accident rate (instead of accident number) is used to identify hazardous location, there is bias towards selecting low-flow locations with few accidents. B. False A. True 5. If all cars on one lane move at 25 mph and all cars on the second lane move at 30 mph, the time mean speed and space mean speed calculated for the 2-lane highway will be the same: Α. True B. False
Compute average space headway for a traffic stream displays average vehicle * ,time headway of 2 sec at space mean speed 60 Kph
Consider the following data: · Average number of vehicles (overtaking - overtaken) = 1 • Average number of vehicles during trips in opposite direction of traffic flow = 336 · Average journey time when test vehicle is travelling with the stream = 8 min 31 sec. · Average journey time when test vehicle is travelling against the stream = 7 min 24 sec. Average journey time for the above data is min. %3D
An intersection has a four-phase signal with the movements allowed in each phase and corresponding and saturation flow rates shown in the table below. Phase 1 2 3 4 Allowed movements EB L, WB L EB T/R, WB T/R SB L, SB T/R NB L, NB T/R Analysis flow rate 245, 230 veh/h 975, 1030 veh/h 255, 235 veh/h 225, 215 veh/h Saturation flow rate 1750, 1725 veh/h 3350, 3400 veh/h 1725, 1750 veh/h 1700, 1750 vehh Calculate the sum of the flow ratios for the critical lane groups. O 0.714 O 0.723 0.751 0.702
An intersection has a three-phase signal with the movements allowed in each phase and corresponding analysis and saturation flow rates shown in the table below. Assume the lost time is 4 seconds per phase and a critical intersection v/c of 0.90 is desired. Phase 1 2 3 Allowed movements NB L, SB L NB T/R, SB T/R EB L, WB L EB T/R, WB TR Analysis flow rate 330, 365 veh/h 1125, 1075 veh/h 110, 80 veh/h 250, 285 veh/h Saturation flow rate 1700, 1750 veh/h 3400, 3300 veh/h 650, 600 veh/h 1750, 1800 vehh Calculate minimum cycle length O 255 sec O 60 sec O 155 sec O 100 sec