Courteous Autonomous Cars

TL;DR

This paper proposes incorporating courtesy into autonomous car decision-making, enabling cars to behave more considerately towards human drivers, which improves safety and aligns with human driving behaviors.

Contribution

It introduces a formal courtesy term in the autonomous vehicle's objective function, allowing cars to consider the impact of their actions on human drivers.

Findings

Courteous cars leave more space when merging in front of humans.

Courtesy term helps explain real human driver behavior.

Courtesy improves interaction safety and realism.

Abstract

Typically, autonomous cars optimize for a combination of safety, efficiency, and driving quality. But as we get better at this optimization, we start seeing behavior go from too conservative to too aggressive. The car's behavior exposes the incentives we provide in its cost function. In this work, we argue for cars that are not optimizing a purely selfish cost, but also try to be courteous to other interactive drivers. We formalize courtesy as a term in the objective that measures the increase in another driver's cost induced by the autonomous car's behavior. Such a courtesy term enables the robot car to be aware of possible irrationality of the human behavior, and plan accordingly. We analyze the effect of courtesy in a variety of scenarios. We find, for example, that courteous robot cars leave more space when merging in front of a human driver. Moreover, we find that such a courtesy term can help explain real human driver behavior on the NGSIM dataset.