1. An isolated intersection is controlled by a two-phase pre-timed signal with the movements allowed in each phases, and corresponding analysis and saturation flow rates shown in Table 1-1. Assume the start up loss time is 2 seconds per phase and the clearance loss time is 3 seconds per phase. The traffic flow accounts for the peak 15- min period and there is no initial queue at the start of analysis period. Progression adjustment factor PF=1.0. Please answer the following questions: (1) What are the optimal cycle length (round up to nearest 5 seconds) using Webster's optimum cycle length formula and effective green times (based on lane group v/c equalization)? (2) What is the northbound approach delay and level of service? Table 1-1 Phase and Flow Data for the Intersection Phase Allowed movements 1 2 NB T/R/L, SB T/R/L EB T/R/L, WB T/R/L Analysis flow rate Saturation flow rate 800, 820 2800, 2900 1120, 960 3000, 3200

1. An isolated intersection is controlled by a two-phase pre-timed signal with the movements allowed in each phases, and corresponding analysis and saturation flow rates shown in Table 1-1. Assume the start up loss time is 2 seconds per phase and the clearance loss time is 3 seconds per phase. The traffic flow accounts for the peak 15- min period and there is no initial queue at the start of analysis period. Progression adjustment factor PF=1.0. Please answer the following questions: (1) What are the optimal cycle length (round up to nearest 5 seconds) using Webster's optimum cycle length formula and effective green times (based on lane group v/c equalization)? (2) What is the northbound approach delay and level of service? Table 1-1 Phase and Flow Data for the Intersection Phase Allowed movements 1 2 NB T/R/L, SB T/R/L EB T/R/L, WB T/R/L Analysis flow rate Saturation flow rate 800, 820 2800, 2900 1120, 960 3000, 3200

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 9P

See similar textbooks

Similar questions

2. Congestion starts at 6am in an expressway. Survey found out that an average of 600vph entered the expressway for the 1* 30minutes, reduced to 250vph and remain constant for the succeeding hours. The booth teller took approximately 10sec to render its service for every vehicle. a. Determine the time of dissipation b. Calculate the total number of vehicles entered for this duration Determine the queue and delay after 45mins from the start of rush hour d. Calculate the delay experienced by the 100th vehicle C.
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
Exercise 6 A three phase signal design is given below. ● ● ● Hic Signal 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 2 3 -200 20 SB 30 100- Lane group SB NB EB WB 400 1000 NB 150 50 300 30 WB Saturation Flows 3400 veh/hr 3400 veh/hr 1400 veh/hr 1400 veh/hr
A turning movement count and a saturation flow study were conducted at a major intersection on an expressway with configuration as presented in Fig.1. The peak-hour volumes and saturation flows obtained from the studies for each movement are presented in Tables 1 and 2, respectively. Using the Webster method, determine a suitable preset signal timing for the intersection using a phasing plan that will yield the minimum cycle length out of all possible phasing plans. Also provide a diagrammatic representation of the signal sequence at the intersection. Assume a yellow interval of 3s, all-red interval of 2s and a peak hour factor of 0.95 for all the approaches. Note: No two movements should conflict during the determination of the phasing plan. Tur F Fig.1: Traffic Movements at a Major Intersection N
Problem 17.2W You are given the following design hourly volume (pc/h) of an intersection with 4 approaches, all without an exclusive right-turn lane. In the following table, fill in the volumes and use them to determine the 8 NEMA movements. Fill in the movement numbers 1 to 8 in the last row of the table.
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 T/R, WB T/R 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 veh/h Using v/c equalization ratio, calculate the effective green time for phase 1 O 15.954 sec O 12.105 sec O 14.127 sec O 13.190 sec
Vehicles are approaching east of a stop signal traveling at 56 km/h, with a density of 46 vehicles/km/lane. The duration of the red signal indication for this approach is 30 seconds. If the saturation flow is 1900 vehicles/hr/lane with a density of 52 vehicles/km/lane and the congestion density is 125 vehicles/km/lane, determine the length of the queue at the end of the red phase. Assume the ShockWave model for the respective analysis.
A turning movement count and a saturation flow study were conducted at a major intersection on an expressway with configuration as presented in Fig.1. The peak-hour volumes and saturation flows obtained from the studies for each movement are presented in Tables 1 and 2, respectively. i) Using the Webster method, determine a suitable preset signal timing for the intersection using a phasing plan that will yield the minimum cycle length out of all possible phasing plans. ii) Also provide a diagrammatic representation of the signal sequence at the intersection. Assume a yellow interval of 3s, all-red interval of 2s and a peak hour factor of 0.95 for all the approaches.
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.
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
Three-phase a pretimed signalized system for T- intersection, the total lost time per phase is 15 sec. Given that PHF for intersection is 0.91. The table below shows information for all movements included in each phase. (Assume the intersection is isolated, and the traffic flow accounts for the peak 15-min period, and there is no initial queue at the start of the analysis period.) 1 Phase Direction Lane group Number of Lanes Volume (veh/h) 2 Northbound Southbound Northbound LT TH & RT ΤΗ I I 250 1800 390 1800 1 270 1600 2- Determine the average vehicle delay for each traffic lane. 3- Evaluate the level of service (LOS) for each traffic lane. 3 Westbound LT 1 250 2500 Saturation flow (veh/lane/hr) 1- Using the Webster method, determine the optimum cycle length and the effective green time for each phase.
An intersection has a three-phase signal with the movement 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 Movement NB L, SB L NB T/R, SB T/R EB L, WB L EB /T/R, WB T/R 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, 300 veh/h 650, 600 veh/h 1750, 1800 veh/h Calculate the Following: 1.)Sum of flow ratios for critical lane groups 2.)minimum cycle length 3.)using v/c equation ratio, calculate the effective green time for phase 1 4.)using v/c equation ratio, calculate the effective green time for phase 2 5.)using v/c equation ratio, calculate the effective green time for phase 3