Sub-problem 3b: Pedestrian Level of Service

In pedestrian delay calculations, how do you arrive at the effective green time for pedestrians? In general, you would use the effective green time for the concurrent traffic movement minus the flashing don't walk time. The effective green time wouldn't be the average effective green time, as we would want to consider only those phases where there was a pedestrian call.

Why? Minor street green allocation is less than that for the major street. When a pedestrian call is present, additional green time needs to be assigned to the minor street approach to accommodate pedestrians' longer crossing time across the wider, major roadway. If we were to use an average phase time, we would include phases where no pedestrian call was present, thereby reporting a lower minor street effective green time.

When we calculate pedestrian delay, we assume that pedestrian compliance is 100%. This means that a pedestrian arriving at the start of the flashing don't walk will wait until the next cycle, and a pedestrian waiting while no conflicting traffic is present will also wait. However, we also assume that all vehicles, especially in regards to channelized right-turn on reds, obey the right-of-way and yield to pedestrians.

Pedestrian characteristics may also affect pedestrian delay. At an intersection of two major roadways, a pedestrian that hits both push-buttons may have to longer than if they were to hit the correct one. Further complicating the analysis, some high-volume roadway intersections expect pedestrians to wait at a center median before finishing their crossing.

These are some of the factors that must be considered when analyzing pedestrian level of service. In most cases, the pedestrian delay equation will be a worst-case analysis scenario that gives an upper-bound to pedestrian delay. However, under certain circumstances this may not be the case.