Considering that 1) you are supposed to keep sufficient distance to break even if the vehicle/generic object in front of you suddenly freezes in space, e.g. a m

Considering that 1) you are supposed to keep sufficient distance to break even if the vehicle/generic object in front of you suddenly freezes in space, e.g. a massive wall flush with the rear end of the vehicle in front of you suddenly appears, and 2) the only things that could conceivably rear end an emergency breaking Uber/Volvo would be bikes and other >=4 wheel vehicles (cars/trucks/etc.), which either drive carefully anyway ((non-)motorized bikes), or have a low probability of human damage (cars/trucks), false positives should be preferred to false negatives by somewhere between 5:1 and 1000:1. The latter only if the following vehicles are civilized enough to hold the distance. The car could figure this in, and computer probabilities for what damage an emergency maneuver would cause, which means that it'd break for a stray cat if it's otherwise alone on the road and the surface is dry. But it won't break for a wolf if it's tailgated by a truck, but potentially even accelerate, to make up for the loss of momentum (but light the rear break lights, to stop as soon as it registers the truck to slow down).