Cars are a massively dominating factor in every traffic safety situation. The number of deaths from bicycle and pedestrian collisions (so, any collision not in

Cars are a massively dominating factor in every traffic safety situation. The number of deaths from bicycle and pedestrian collisions (so, any collision not involving a ton of metal) is on the order of a single death every few years, and it generally involves people that (for lack of a better description) are at a point in life where any injury, just a fall, is very much life-threatening. The key to reducing traffic deaths is to not have multi-ton cars with power in excess of 50kW crash into squishy humans. There is no amount of polystyrene in the world to diminish the forces involved here.