Automated driving is a safety critical process, which requires complex decision making. In order to validate driving decisions, it is possible to maintain at all times a contingency maneuver, which transfers the vehicle to a safe standstill, if other decision making processes fail. In this paper we present a motion planner, which computes contingency maneuvers for an automated vehicle in a 0.1[s] time frame. A discrete set of motion primitives is assembled in a heuristic best-first search. In order to speed up the search, an obstacle sensitive heuristic is applied, which maintains properties of bounded sub-optimality and completeness. A run-time comparison with and without the obstacle sensitive heuristic is presented on two exemplary collision avoidance scenarios.