Full Stop Ahead
The driver needs to have enough space to stop if needed, so a safe distance between cars would depend on your speed. Also, gravity would still be pushing against the car, making it go forward.
Suppose you are driving on a dry road with 150 ft (about 10 car lengths) between your car and the car in front of you. Whats the maximum speed you should be traveling? 64-65 mph is the maximum speed you should be traveling.