How does autonomous ride-hailing pricing shape modal shifts and travel equity?

Autonomous ride-hailing (ARH) could reshape urban mobility by sharply reducing operating costs, since driver wages make up a large share of those costs, and by enabling transportation network companies to set flexible prices through centralized algorithms. As ARH can serve both as a door-to-door mode and as a feeder to metro systems, its pricing may have complex effects on public transit use and travel equity, yet these dynamics remain insufficiently explored. To fill this gap, this study develops a multimodal framework integrating human-driven ride-hailing, ARH, and metro services to estimate modal splits under varying ARH fare scenarios in Chicago. Travelers' price sensitivity is captured through a willingness-to-use function. Model validation against observed mode shares yields reasonable performance. The results reveal a nonlinear demand response: ARH fare reductions lead to a substantial increase in the use of ride-hailing as a first- and last-mile feeder to metro, and a decline in conventional metro access by walking and bus, but only a moderate increase in door-to-door ride-hailing use. Despite this moderate increase, vehicle miles traveled rise more sharply because ARH with lower prices increasingly displaces long-distance metro trips. At the same time, lower ARH prices can reduce travel time and monetary cost while narrowing equity gaps, with the largest benefits occurring in disadvantaged, metro-poor areas. Overall, the findings underscore the importance of regulating ARH prices to balance efficiency, transport sustainability, and travel equity. • Autonomous ride-hailing (ARH) serves as a direct and first−/last-mile travel mode. • A simulation-based multimodal framework captures RH and metro interaction. • Lower ARH fares mainly increase RH–metro use rather than door-to-door RH use. • Affordable ARH fares reduce travel time and cost, especially in underserved areas. • Reduced ARH prices narrow travel inequities but increase VMT and congestion.