I’ve felt it has been fudging the fact that our character can see farther than the player and would be able to react to obstacles and decelerate better than we can through the interface. So when I go from 30 to 0 with one press of the period key I assume my character would be decelerating at a sensible rate in the time frame previous to that and the movement has just been averaged out for game arbitration purposes.
That’s my personal rationalization anyway. That being said, I wouldn’t be opposed to some kind of inertia or momentum system.
I still don’t know how people travel more than ≈45 mph without crashing in to something. (Even zoomed out.)