Abstract: Systems and techniques for determining a trajectory for use in controlling a vehicle are described. A trajectory determination system may generate a variety of trajectories for potential use in controlling a vehicle, including a maximum braking trajectory that enables the maximum application of the vehicle's brakes. A vehicle computing system may determine a distance between vehicle and an obstacle and stopping distances for the various trajectories and implement the maximum braking trajectory after determining that the distance to stop for that trajectory is the same as, but not substantially greater than, the distance between the vehicle and the obstacle.