Variability of Travel Times on Arterial Links: Effects of Signals and Volume

We use detailed probe, video and detector data to characterize variability of travel times on (one link of) a major arterial street in the Northwest suburbs of Chicago. Major influences on variability are shown to be signal status and traffic volume, vehicles’ entry times of the link relative to the start of a red phase at the downstream intersection and the numbers of cars queued when they arrive at that signal. Because these primary determinants of travel time are not accessible in many situations, we show how to predict them from others that are more readily available.