Physical conditioning should be a key element in any survival "kit". I've gone through both the Navy's old Dilbert Dunker and the newer Helo Dunker. Both of those devices are relatively gentle water entries compared to a car falling into the water during a bridge collapse. Add parts of the bridge and moving water, and IMO getting out of the car at all will be a major challenge.

The last time I did the helo dunker I did a lot of swimming underwater conditioning myself. For someone to survive this in cold river water never having thought about the procedures (let alone actually practiced in a trainer) would be a miracle.