Universally Safe Swerve Maneuvers for Autonomous Driving

This paper characterizes safe following distances for on-road driving when vehicles can avoid collisions by either braking or by swerving into an adjacent lane. In particular, we focus on safety as defined in the Responsibility-Sensitive Safety (RSS) framework. We extend RSS by introducing swerve maneuvers as a valid response in addition to the already present brake maneuver. These swerve maneuvers use the more realistic kinematic bicycle model rather than the double integrator model of RSS. When vehicles are able to swerve or brake, it is shown that their required safe following distance at higher speeds is less than that required through braking alone. In addition, when all vehicles follow this new distance, they are provably safe. The use of the kinematic bicycle model is then validated by comparing these swerve maneuvers to that of a dynamic single-track model. The analysis in this paper can be used to inform both offline safety validation as well as safe control and planning.