Evaluating Segment-Level Active Mode Shift Potential Using Desire Lines

Understanding which active transportation facilities have a high potential for shifting car trips to active modes is a potent metric of success for funders seeking to make high impact transportation investments. This paper documents the development and validation of a traveler alignment analysis tool that evaluates the orientation, proximity, and magnitude of trips by distance in origin–destination (OD) desire line data to evaluate mode shift potential at the segment level. This alignment analysis operates by using line features created by a Utah statewide OD matrix of vehicle trips taken from the Replica Places activity-based modeling data platform. Additionally, the research tests the implementation of jittering, a previously proposed method for OD line disaggregation, and the impact on traveler alignment performance. To tune parameters related to proximity, angle, and trip distance, a sensitivity analysis was conducted comparing similar mode shift potential trips generated by the proposed Traveler Alignment tool and 25 StreetLight Data pass-through zone analyses. This sensitivity analysis used a mean absolute error metric to minimize estimation error and understand how altering parameters and applying jittering affected tool performance. A Pearson correlation test indicates a significant, positive linear relationship (p < 0.01) between Traveler Alignment tool outputs and results of the select-link analysis, indicating that this method produces reasonable results that may be used to evaluate different projects comparatively for their active mode shift potential.