Near Side, Far Side, Uphill, Downhill

Abstract

One of the factors affecting where bus stops should be located is the expected delay associated with the stop location. On hills, the effect of gravity on already weak diesel engines can lead to considerable additional delay if a bus has to accelerate from a stop. An empirical bus acceleration profile, modified to account for gravity, was applied to constant grade, sag curve, and crest curve profiles. The marginal impact of grade on stopping delay ranged from –4 to 11 s, depending on grade. At signalized intersections, a deterministic model was created that accounted for deceleration, acceleration, and queue interference. Relative to a stop placed away from an intersection, far-side stop placement either causes a very small reduction in delay or has no effect. Near-side placement can reduce delay in a few cases such as reserved bus lanes, but more often it increases delay, sometimes considerably depending on factors such as red ratio, volume:capacity ratio, cycle length, and stop setback. Measures that reduce interference with the queue tend to reduce the net delay from a near-side location; these measures include increasing stop setback, shortening cycle length, and giving the bus a (near) exclusive lane. Results are presented with default adjustments for hills and signalized intersections that can be used in the context of a stop spacing study.