1. An autonomous coverage robot comprising: a drive system configured to maneuver the robot according to a heading setting and a speed setting; a bump sensor responsive to a collision of the robot with an obstacle in a forward direction; and a proximity sensor responsive to a potential obstacle forward of the robot; wherein the drive system is configured to reduce the speed setting in response to a signal from the proximity sensor indicating detection of a potential obstacle, while continuing to advance the robot according to the heading setting; and wherein the drive system is configured to alter the heading setting in response to a signal received from the bump sensor indicating contact with an obstacle.