Estimating Pedestrian Volumes at Each Crosswalk of Intersections: Comparison of Land-Use Models and Short-Term Count Methods

Abstract

Estimating pedestrian exposure for all the intersections in a jurisdiction is crucial for developing strategies with a focus on pedestrians. Some engineering applications require the annual average daily pedestrian traffic (AADPT) to be disaggregated per crosswalk. When continuous counts are available at the intersection, this indicator can be calculated directly. However, when only short-term counts (STCs) or no information on pedestrian volume is available, the AADPT per crosswalk cannot be calculated and must be estimated using other means. This work (1) evaluated the degree of confidence for estimating the pedestrian volume in each crosswalk based on point estimates of percentage shares per crosswalk obtained from STCs; and (2) developed models to estimate the percentage share of pedestrian volume per crosswalk as a function of attributes of the intersection that commonly are available for jurisdictions, referred to as the land-use (LU) model. The two methods were evaluated using continuous count data from three different jurisdictions, and a naive estimate assuming equal shares per crosswalk was used as a benchmark. The performance of each method was measured as the fraction of the intersection AADPT that was allocated wrongly to each crosswalk. The use of the LU model generated an average wrong allocation of 0.301, a statistically significant improvement of 11.4% compared with the naive estimate. The use of a STC from a single day produced an average wrong allocation of 0.153, an improvement of 54.9% from the naive estimate. Increasing the number of days of STCs to two or three resulted in average performance indicators of 0.117 and 0.106, respectively. The benefits of using STCs for more than three days are minimal. The STC method was developed using STCs from the same 1-year period in which the observed share was averaged. In practice, STCs are likely to be between 1 and 5 years old. Analysis using STCs from previous years showed that estimation error in practice may be as much as twice as large as the aforementioned errors.