An answer that fits a “driver” (assuming this means of a driver other than a
motorcyclist) and a motorcyclist is: safe following distance.
Mathematically you should allow one car length for every 10mph of movement to stop safely.
For example if a vehicle you are following is traveling at 50mph and you are following behind them, you should be a minimum of 5 car lengths away from their rear bumper. If going 70mph, it’s 7 car lengths, and so on.
