Go the Distance: How Speed Affects Braking Distance

A lot of different factors can affect your braking distance. Braking distance is a measurement of how far your vehicle travels during the time it takes to come to a complete stop once you hit the brakes. Your braking distance will be shorter (aka better) if your brakes and tires are in good condition. That means you should make sure your tires have the right air pressure level and plenty of tread.

No matter how nice or well cared for your vehicle is, the best indication of your braking distance will be your speed. Watch how a vehicle’s speed changes its braking distance.

Thinking Distance

Thinking distance is how far your vehicle travels during your reaction time. When you see a potential threat, sign, or traffic control on the road, you don’t break instantaneously. You may need a second or two to move your foot to the brake pedal. Reaction time can be slowed down if the driver is sleepy, sick, impaired, or distracted. Make sure you’re sober and alert every time you drive, because sometimes an extra second can make all the difference.

fatigue makes you reaction distance longer
Don’t drive while sleep deprived!

Total Stopping Distance

The equation for figuring out how far your car will go from the moment you see a hazard to the moment you’re stopped is thinking distance plus braking distance. The faster you’re driving, the more ground you’ll cover as you react and start braking. Makes sense, right? Braking distance is a little crazier because it increases exponentially. So if you double your speed, you’re braking distance doesn’t double as well. It quadruples! Check out the total stopping distance equations below for vehicles driving at various speeds.

braking distance increases exponentially with speed
The faster you drive, the harder it is to stop.

60 mph: Thinking Distance of 60 feet + Braking Distance of 180 feet = Total Distance of 240 feet

40 mph: Thinking Distance of 40 feet + Braking Distance of 80 feet = Total Distance of 120 feet

20 mph: Thinking Distance of 20 feet + Braking Distance of 20 feet = Total Distance of 40 feet