4) Accuracy and Spatial Transferability of Direct Demand Models for Estimating Pedestrian Exposure (Annual Average Daily Pedestrian Traffic Counts) at Signalized Intersections
Direct demand (DD) models are used to estimate pedestrian volumes at intersections as a function of readily available variables, such as land use and socioeconomic features. The objectives of this paper are to (1) identify and qualitatively assess existing DD models in the literature; and (2) evaluate the spatial transferability of DD models for estimating Annual Average Daily Pedestrian Traffic (AADPT) at signalized intersections. Six DD models developed from jurisdictions with varying characteristics were selected for spatial transferability assessment. The models were applied to three jurisdictions (Milton, Canada; Pima County, US; and Downtown Toronto, Canada), that had notable differences in the level of pedestrian activity, land use, and socioeconomics. Observed pedestrian volumes were obtained for sites in each jurisdiction. The DD models performed considerably differently across jurisdictions. Five of the models performed reasonably well for Milton, a jurisdiction that is comparable to those considered in the calibration of the selected DD models and that shares characteristics with many suburban Canadian and US jurisdictions. Overall, the applications for Pima County and Downtown Toronto, which are associated with extremely low and high pedestrian volumes, respectively, provided poor accuracy. This paper demonstrated the potential for transferring existing DD models to other jurisdictions; but also identified the clear need for further research to improve the spatial transferability of DD models.
Paper entitled “Comparing Direct Demand Models for Estimating Pedestrian Volumes at Intersections and Their Spatial Transferability to Other Jurisdictions” was presented at Annual Meeting of the Transportation Research Board in Washington DC Jan. 8 – 12, 2023.