Originally Posted by Polaris OBark

I think it would be more along the lines of rear-end collision, where the driver who rear-ends the other one is presumed to be at fault unless there are exceptional circumstances. (The idea is if you are following too closely to be able to stop in time to avoid a collision, you are at fault. A similar situation would obtain with car vs. bicycle collisions. This doesn't preclude the cyclist being at fault, but assumes given normal, legal behavior, the driver has the responsibility to avoid the collision.)