a) Refer to the intersection shown in Figure 1. Use cross-product guidelines to determine if protected left-turn phases should be provided for any of the approaches and plot timing stages [5 pts]. 300 200 60 70 300 100 900 1000 Both roadways are level (zero grade) 200 350 90 50 Peak-hour traffic volumes 60 ft Maple Street Approach speed 40 mi/h Vine Street Approach speed 35 mi/h TABLE 1 Saturation Flow Rates for Three-Timing Stage Design at Intersection of Maple and Vine Street Timing Stage 1 EB L: 1700 vph Timing Stage 2 EB Th/R: 3400 vph Timing Stage 3 SB L: 450 vph NB L: 475 vph Maple Street Approach speed 40 mi/h WB L: 1700 vph WB Th/R: 3400 vph SB Th/R: 1800 vph NB Th/R: 1800 vph Vine Street Approach speed 35 mi/h 36 ft Figure 1 Intersection geometry and peak traffic volume b) Determine the lane groups to use for analysis of the Maple and Vine Street intersection. To simplify the analysis, we assume that adjacent exclusive through lanes and shared through/right- turn lanes will be combined into one lane group [5 pts]. c) Calculate the sum of the flow ratios for the critical lane groups for the timing plan determined in previous question given the saturation flow rates in Table 1 [5 pts]. d) Calculate the minimum and optimal cycle lengths for the intersection of Maple and Vine Streets, using the information provided in the preceding problems, for both the three-timing-stage and four-timing-stage design. The total cycle lost time was determined to be 12 seconds. Assuming X for the intersection is 0.9 [5 pts]. e) Determine the green-time allocations for the Cmin cycle length found in the previous question, using the method of v/c ratio equalization [5 pts]. f) Determine the yellow and all-red times for vehicles traveling on Vine and Maple Streets [5 pts] g) Determine the minimum amount of pedestrian green time required for the intersection of Vine and Maple Streets. Assume a maximum of 15 pedestrians crossing either street during any one phase and a crosswalk width of 8 ft [5 pts].

a) Refer to the intersection shown in Figure 1. Use cross-product guidelines to determine if protected left-turn phases should be provided for any of the approaches and plot timing stages [5 pts]. 300 200 60 70 300 100 900 1000 Both roadways are level (zero grade) 200 350 90 50 Peak-hour traffic volumes 60 ft Maple Street Approach speed 40 mi/h Vine Street Approach speed 35 mi/h TABLE 1 Saturation Flow Rates for Three-Timing Stage Design at Intersection of Maple and Vine Street Timing Stage 1 EB L: 1700 vph Timing Stage 2 EB Th/R: 3400 vph Timing Stage 3 SB L: 450 vph NB L: 475 vph Maple Street Approach speed 40 mi/h WB L: 1700 vph WB Th/R: 3400 vph SB Th/R: 1800 vph NB Th/R: 1800 vph Vine Street Approach speed 35 mi/h 36 ft Figure 1 Intersection geometry and peak traffic volume b) Determine the lane groups to use for analysis of the Maple and Vine Street intersection. To simplify the analysis, we assume that adjacent exclusive through lanes and shared through/right- turn lanes will be combined into one lane group [5 pts]. c) Calculate the sum of the flow ratios for the critical lane groups for the timing plan determined in previous question given the saturation flow rates in Table 1 [5 pts]. d) Calculate the minimum and optimal cycle lengths for the intersection of Maple and Vine Streets, using the information provided in the preceding problems, for both the three-timing-stage and four-timing-stage design. The total cycle lost time was determined to be 12 seconds. Assuming X for the intersection is 0.9 [5 pts]. e) Determine the green-time allocations for the Cmin cycle length found in the previous question, using the method of v/c ratio equalization [5 pts]. f) Determine the yellow and all-red times for vehicles traveling on Vine and Maple Streets [5 pts] g) Determine the minimum amount of pedestrian green time required for the intersection of Vine and Maple Streets. Assume a maximum of 15 pedestrians crossing either street during any one phase and a crosswalk width of 8 ft [5 pts].

Traffic and Highway Engineering

5th Edition

ISBN:9781305156241

Author:Garber, Nicholas J.

Publisher:Garber, Nicholas J.

Chapter8: Intersection Control

Section: Chapter Questions

Problem 8P

See similar textbooks