Computer-implemented methods and systems for estimating liability for a vehicle accident are provided. In one embodiment, theoretical paths of a reference vehicle and a reacting vehicle may be estimated. In an embodiment, a reacting vehicle reacts to a danger of an accident with the reference vehicle. The opportunity of the reacting vehicle to avoid the accident may be assessed. In certain embodiments, whether the reacting vehicle had an opportunity to avoid the accident at a specified speed may be assessed. A contribution to liability to the reacting vehicle may be estimated based on the opportunity of the reacting vehicle to avoid the accident.