UC Irvine

Public transit agencies exist to provide equitable access to travel. This mission often requires operating full-size buses or trains during times and in areas with very low demand, resulting in unnecessarily high operating costs. Meanwhile, app-based transportation network companies (TNCs) offer flexible, on-demand, point-to-point service. This research evaluates whether, and under what conditions, transit agencies can replace low-productivity bus segments with TNC services without any worsening of access equity.This study develops a three-stage decision framework to: (1) identify low-demand segments using a stop-level screening method, (2) assess operational feasibility and cost-effectiveness of point-to-point TNC service through an optimization model based on a multi-vehicle pickup-and-delivery problem with time windows (by presenting possible contractual structures for the partnership), and (3) create predictive tools that estimate potential for TNC substitution of transit without running the computationally expensive optimization model. Results from a Long Beach Transit case study show that service-segment truncation, such as with short-turning of transit vehicles and TNC substitution for the remaining line segment, can reduce operating costs by up to 60% while improving passenger utility by approximately 50%.The proposed optimization formulation is flexible and can be applied to different spatial demand patterns, varying frequency, passenger density, and coordinated TNC substitution on multiple routes. The framework can also be used for other comparable service options, such as stop-to-stop TNC pickup, individually subsidized rides, and demand-responsive shuttles as well as for comparisons against the proposed door-level (curb to curb) service. Regression models and bivariate correlations identify key criteria that help agencies determine when segment truncation and TNC substitution are likely to succeed. Transit agencies operating under different network geometries and demand conditions can use the framework as a practical, step-by-step method to assess TNC substitution and to manage the process from initial contracting to piloting and full-scale operation.Real-world pilots in Dallas, Los Angeles, and Pinellas County confirm that TNC substitution preserves access when agencies maintain control over fare integration, incentives, and service rules through clear contracting. The purpose here is not to advocate TNC substitution as a way to reduce transit service; rather, TNC substitution enables agencies to reallocate resources. Such reallocation, as in the case of short-turning of transit service considered here, can increase the frequency on the segments served by transit, which in turn can conceivably induce more demand as well. Transit operations can then be more focused on the segments where demand is highest, with TNC operations continuing to give the same level of service in the less-productive segments. As induced demand from such reallocation is not studied herein, the estimated benefits of TNC-substitution in this research can be considered conservative.