Problem 1: Maxwell Drive

Base Case Phasing

The base case signal phasing is shown in Exhibit 2-5. The first phase is eastbound-westbound with a permitted eastbound left. The second is eastbound only with a protected eastbound left. The third phase is southbound. This intersections uses actuated control, and field data suggest that phase 1 lasts 20-40 seconds. Phase 2 is skipped about half the time; and when it is called, it lasts 8-12 seconds. Phase 3 lasts 10-18 seconds. The cycle length ranges from 30-70 seconds and averages 48 seconds. 

Exhibit 2-6 shows the intersection volumes for the base case AM and PM peak hours. In the AM peak, the largest volumes are the eastbound through and the westbound through. In the PM peak, the volumes are very similar but they are larger, especially the turning movements (e.g., 215 westbound right turns in the PM peak versus 84 in the AM peak.)

Discussion:
We've focused here on the phasing and the volumes. What other data do we need to do the analysis? Take a few minutes to examine the HCM signalized methodology to make sure you know what that complete list of data items is. Think about the implicit assumptions we're making about other data items.