The Reaction Distance is the distance the car travels in the three-quarters of a second that it takes for a driver to react to a problem and apply the brakes.

The Braking Distance is the distance traveled from the time the brakes are first applied to the time the car comes to a complete stop.

The Stopping Distance is the total distance it takes to stop the vehicle, from the moment the driver sees a problem to the time the car is stopped completely.

Reaction Distance + Braking Distance
= Stopping Distance.

Remember:

Steering will be easier if you have a "big picture" of your intended path of travel. Keep enough space between your car and the car in front of you, so that it does not block your view. Driving in the center of the lane, instead of hugging one side or the other, improves your view of the roadway.

Following too closely causes most rear end accidents. To avoid this, use the "three-second rule."  When the vehicle ahead of you passes a certain point, such as a sign, count "one-thousand-one, one-thousand-two, one-thousand-three."   This takes about three seconds. If you pass the same point before you finish counting, you are following too closely.  At faster speeds the distance should be greater.

Sometimes you will need more than a three-second cushion -- give yourself four seconds or more.

	When a tailgater crowds you, you should allow extra room between your car and the car ahead. Then, if you need to slow down, you can do so gradually. You will be able to avoid braking suddenly and being hit from behind by the tailgater!
	On slippery roads, if the car ahead should slow or stop, you will need more distance to stop your car.
	When following motorcycles, if the motorcycle falls, you will have to avoid hitting the rider. Motorcycles fall more often on wet or icy roads, on metal surfaces such as bridge gratings or railroad tracks, and on gravel.
	When the driver behind you wants to pass, slow down to allow room in front of your car so the driver will have space to move into.
	When you are pulling a trailer or carrying a heavy load, the extra weight makes it harder to stop.
	When following large vehicles that block your view ahead, you will need the extra room, four seconds gives you to see around the vehicle and to the sides.
	When you are stopped in traffic on a hill, the vehicle ahead may roll back into your car when it starts moving.
	When you see a bus, school bus, or vehicle carrying flammables, remember that these vehicles must stop at railroad crossings. Expect the stops and slow down early to allow plenty of room.
	When merging on a freeway, you need the extra time.

When you follow too closely and another driver "cuts" in front of you, the normal reaction is to slam on your brakes and swerve out of the way. Swerving out of the way most often results in cutting someone else off or possibly driving off the roadway. It might also result in the car behind you crashing into you or into other cars around you. If another driver "cuts" in front of you, just take your foot off the gas. This will give you space between your car and the other car, and you can avoid swerving into another lane. Don’t overreact if you are cut off. 

Plan your emergency escape route before
an emergency happens.

Keep A Cushion to the Side

Keep a space cushion on each side of your car.