Sub-problem 2b: Moe Road PM peak hour - With Conditions

What if you had forgotten to take account of the lane utilization factor? What would happen if you didn’t enter the correct values of 0.81 for the westbound throughs and 0.88 for the eastbound throughs? What results would you get in the second run? As the third run shows in Exhibit 2-25, the average delay would have been 20.1 seconds instead of 23.9; the eastbound through would have shown a delay of 21.4 seconds instead of 28.2. That’s a difference of 25%. The westbound through would have shown a delay of 11.7 seconds instead of 14.7, which is a difference of 20%. This demonstrates the importance of using the lane utilization factor.

What if the lane utilization was actually worse than what we saw on the day we observed the traffic? What would be the intersection’s performance if the westbound lane utilization were (75%, 25%) instead of (57%, 43%)? As the fourth run shows, the answer is that the westbound delay would be 29.0 seconds instead of 18.3, (58% larger) and the average delay would be 29.5 seconds instead of 23.9 (17% larger).

Discussion:
Can you think of intersections where lane utilization is an issue? How have you handled it in the past? How important was it to take it into account? Have you thought about doing lane-by-lane analysis? Would that help? What about simulation? Do simulation models let you consider lane utilization?