A three phase signal design is given below. What is the sum of the flow ratios for the critical lane groups? What is the total lost time for a signal cycle assuming 2 seconds of clearance lost time and 2 seconds of startup lost time per phase? What is the cycle length using Webster Method? ● ● EB Phase 1 23 200 20 SB 30 150 100- Lane group SB NB EB WB + 400 1000 4 <50 NB 30 300+ WB Saturation Flows 3400 veh/hr 3400 veh/hr 1400 veh/hr 1400 veh/hr

A three phase signal design is given below. What is the sum of the flow ratios for the critical lane groups? What is the total lost time for a signal cycle assuming 2 seconds of clearance lost time and 2 seconds of startup lost time per phase? What is the cycle length using Webster Method? ● ● EB Phase 1 23 200 20 SB 30 150 100- Lane group SB NB EB WB + 400 1000 4 <50 NB 30 300+ WB Saturation Flows 3400 veh/hr 3400 veh/hr 1400 veh/hr 1400 veh/hr

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter8: Intersection Control

Section: Chapter Questions

Problem 12P

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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?
16 ut of age Which of the following occurs in Interrupted Flow Facilities? Select one: A. External interruptions exists B. Frequent signals and stop/yield signs C. Platoons of vehicles in traffic stream D. All of the above OE. B and C Next page
QUESTION 3 Match the term with its definition. ✓ phase ✓ interval ✓ cycle ✓ring ✓ barrier A. the total time to complete one sequence of signalization for all movements at an intersection B. a continuous sequence of phases C. reference within the cycle at which time a phase in each ring terminates, separating conflicting movements such as east-west from north-south D. the time given to opposing left turn movements E. duration of time during which the signal indications do not change F. the green, change and clearance intervals assigned to a specific movement or movements of traffic
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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
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An intersection has a four-phase signal with the movements allowed in each phase and corresponding analysis and saturation flow rates shown in the table below. Phase 1 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 vehh 3350, 3400 veh/h 1725, 1750 veh/h 1700, 1750 veh/h Calculate the optimum cycle length (Assume 4 seconds lost time per phase) O 116.466 sec O 104.693 sec 97.315 sec O 101.399 sec
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