Pre-timed traffic signals are the foundation of a significant section of Ghana's traffic signal systems. In certain cases, phases with high traffic volumes have green periods that are shorter than those with low traffic volumes. Who knows what may be causing this difference in signal timing or how to fix it

Pre-timed traffic signals are the foundation of a significant section of Ghana's traffic signal systems. In certain cases, phases with high traffic volumes have green periods that are shorter than those with low traffic volumes. Who knows what may be causing this difference in signal timing or how to fix it

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter8: Intersection Control

Section: Chapter Questions

Problem 12P

See similar textbooks

Similar questions

Match the term with its definition. ✓ phase interval cycle ring barrier A. the time given to opposing left turn movements B. a continuous sequence of phases c. the total time to complete one sequence of signalization for all movements at an intersection D. reference within the cycle at which time a phase in each ring terminates, separating conflicting movements such as east-west from north-south E. the green, change and clearance intervals assigned to a specific movement or movements of traffic F. duration of time during which the signal indications do not change
A signalized intersection has four approaches. If the north, south, east, and west approaches have average control delays of 21, 25, 34, and 32 seconds, respectively, and their respective volumes are 198, 176, 265, and 303 pc/h, what is the intersection LOS? Group of answer choices LOS C LOS B LOS A LOS D
Q4b. What are the relevance of the following considerations in traffic signal timing design? i. Incorporating all-red interval in the inter-green period ii. Conversion of all vehicle categories to passenger car units (PCU)
For designing a 2-phase fixed type signal at an intersection having North-South and East-West road where only straight ahead traffic permitted, the following data are available. Parameter Design North Hour Flow (PCU/hr) 1000 2500 South 700 2500 East 900 3000 West 550 3000 Saturation Flow (PCU/hr) Total time lost per cycle is 12 seconds. The cycle length (seconds) as per Webster's approach is
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
TRANSPORTATION ENGINNERING-TRAFFIC SIGNALS An approach to a predetermined signal has 25 seconds of effective green for a 60 second cycle. The approach volume is 500 vehicles/hour and the saturation flow rate is 1400 vehicles/hour. Calculate the average vehicle delay using D/D/1 queing.
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
i. Describe the major advantages and disadvantages of using traffic signals ii. Why traffic signal cycle timing requires an update from to time to time? iii.Why clearance time is considered as an important period?
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 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
A. On a six-lane EDSA, an observer is stationed at a certain spot. All of the cars in lane 1 are moving at a speed of 75 kph, 62 kph in lane 2, and 100 kph in lane 3, 65 kph in lane 4,80 in lane 5 and 90 for the bus lane respectively. In addition, cars are kept at a constant 85-meter distance between. What will be the time-mean speed and space- mean speed for such a traffic stream based on the acquired spot speed data for all cars as they cross the observation site for 45 minutes? B. Vehicles are known to arrive according to a Poison process at a specific spot on a highway. Vehicles are tallied at 20-second intervals, with 150 of these intervals being 20-second intervals. In 20 of the 150 periods, no automobiles have arrived. Estimate the number of these 150 intervals in which four automobiles arrive at the same time. C. A data was gathered for the 10 vehicles passing in Katipunan Intersection every 15 seconds. Determine the Density, Flow of traffic per hour and space and time mean…
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