A vehicle has wheels, sensors for generating an input data set, and a controller. The controller is in communication with the sensors, including a first sensor for detecting an obstacle on a road surface in a first manner, and adapted to monitor a boundary of the road surface to determine when the wheels are crossing the boundary. A second sensor detects the obstacle in a second manner, and additional sensors determine inertial data of the vehicle. The controller compares the input data set to calibrated thresholds, and determines an appropriate control response such as autonomous braking based on the results. A method optimizes a collision preparation response in the vehicle by measuring the inertial data, detecting the obstacle using a radar or LiDAR device, and monitoring the boundary using an electro-optical device. A supplemental braking force is automatically applied when the vehicle crosses the boundary while the obstacle is detected.