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Sub-problem 2a - Page 2 of 2

ID# C202A02

Sub-problem 2a: Moe Road AM peak hour - Existing Conditions

Exhibit 2-24 presents three model runs that focused on the AM Existing peak hour. Here you can view the input data for the base case (Dataset 15), maximum pedestrians (Dataset 16), and no pedestrians (Dataset 17) conditions.

Exhibit 2-24. Moe Road Treatment for Pedestrians
Dataset Conditions Peds Cycle Length Performance Measure EB WB NB SB OA
LT TH RT Tot LT TH RT Tot LT TH RT Tot LT TH RT Tot
15 Base Case Yes 72.0 Delay 12.6 20.6 20.5 25.6 10.9 14.4 22.8 22.8 19.5 19.5 18.2
16 Max Peds Yes 72.0 Delay 12.6 20.6 20.5 25.6 10.9 14.4 23.6 23.6 19.6 19.6 18.3
17 w/o Peds No 44.0 Delay 7.8 13.4 13.4 16.5 7.4 9.6 16.3 16.3 13.4 13.4 12.2

In the base case, with pedestrians included, the cycle length is 72 seconds and the delays are between 12.6 and 25.6 seconds per vehicle (dataset 15). Interestingly, even if you boost the southbound pedestrians to the maximum limit allowed by the HCM methodology (1,700 pedestrians per hour), the delays change very little. The southbound delay increases from 19.5 seconds per vehicle to 19.6 and the northbound delay increases from 22.8 to 23.6 (dataset 16). So in this instance, the interference between the pedestrians and the vehicular traffic is not significant.

The more significant story relates to what the situation would be without pedestrians. As the third run shows, the delays would drop to 12.2 seconds per vehicle overall, 33% less than the base case. The delays by movement drop from a range of 12.6-25.6 seconds per vehicle to 7.4-16.5 seconds per vehicle (dataset 17). That’s as much as a 35% difference. This happens because we can now use phase times that don’t meet the pedestrian minimums. Instead of using 8, 33, and 21 seconds for phases 1, 2, and 3 (to meet the 21-second minimum for phase 2, given the pedestrians), we can use 3, 20, and 11.

What is learned from this? If pedestrians are present, make sure you account for them when you analyze the intersection. Most importantly, make sure you use green times that meet or exceed the pedestrian requirements.

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