Methods and devices for controlling a vehicle in an autonomous mode are disclosed. In one aspect, an example method is disclosed that includes obtaining lane information that provides an estimated location of a lane of a road on which a vehicle is traveling. The example method further includes determining that the lane information has become unavailable or unreliable and, in response, using a sensor to monitor a first distance and a second distance between the vehicle and a neighboring vehicle, determining first and second relative positions of the neighboring vehicle based on the first and second distances, respectively, and, based on the first and second relative positions, determining an estimated path of the neighboring vehicle. The example method further includes, based on the estimated path, determining an updated estimated location of the lane, and controlling the vehicle based on the updated estimated location of the lane.