# Autonomous Vehicle Route Choice

On real road networks, autonomous vehicles that minimize only their own travel time raise human-driven vehicles' average travel time, because road capacity is shared and the routes that avoid congestion shift cost onto others. The study adds a marginal cost term to the autonomous vehicle reward: a counterfactual simulation removes that vehicle from the network and compares the remaining vehicles' travel times, quantifying its system impact. On the real networks of Ingolstadt and Provins, the social term cuts the increase in human travel time from 1.7% to 1.1% while autonomous vehicles also get faster; computing marginal cost for only about 40% of the most impactful vehicles reduces extra simulations from roughly 4.14 million to about 2.46 million with close performance.

On real road networks, autonomous vehicles that minimize only their own travel time raise human-driven vehicles' average travel time, because road capacity is shared and the routes that avoid congestion shift cost onto others. The study adds a marginal cost term to the autonomous vehicle reward: a counterfactual simulation removes that vehicle from the network and compares the remaining vehicles' travel times, quantifying its system impact. On the real networks of Ingolstadt and Provins, the social term cuts the increase in human travel time from 1.7% to 1.1% while autonomous vehicles also get faster; computing marginal cost for only about 40% of the most impactful vehicles reduces extra simulations from roughly 4.14 million to about 2.46 million with close performance.