TRUCKS NEED MORE TIME TO STOP
Dimensions of an average car or truck
Width: 5′ – 6′ wide
Height: 4′ 6″ – 5′ high (for passenger vehicle) or 6′ 6″ high (for SUVs and some pickup trucks)
Length: Between 12′ – 18′ long
Weight: 3,000 – 4,000 lbs.
Dimensions of an average semi truck
Width: 8′ 6″ wide
Height: 14′ high (measured from level ground to top of load or vehicle)
Length: Lengths vary from 45′ for a single motor vehicle to 65′ for a truck-trailer combination
Weight: 80,000 lbs. gross weight
A typical tractor-trailer or other large truck can weigh as much as 80,000 pounds by law. Most passenger vehicles are about 3,000 – 4,000 pounds. A passenger vehicle weighing 4,000 pounds, traveling under ideal conditions at a speed of 65 miles per hour would take 316 feet to stop (nearly the length of a football field). In comparison, a fully loaded tractor-trailer weighing 80,000 pounds traveling under ideal conditions at a speed of 65 miles per hour will take 525 feet to stop (almost the length of two football fields).
How to determine Stopping Distance
Total stopping distance is the distance your vehicle travels from the time you see a hazard and press on the brake until the vehicle stops. Total stopping distance is made up of three parts:
Perception Distance – The distance a vehicle travels while a driver is identifying, predicting and deciding to slow down for a hazard.
Reaction Time – The time it takes for a driver to execute a decision once a danger is recognized. The distance your vehicle travels while you react is called a reaction distance.
Braking Distance – The distance a vehicle travels from the time a driver begins pressing on the brake pedal until the vehicle comes to a stop.
For trucks, you must also factor in the brake lag distance in the stopping distance. Brake lag is the time it takes for a brake signal to travel to all the wheels on the tractor-trailer (about 3/4 of a second). Brake lag distance is the distance the truck travels before the brakes on the trailer are engaged.
Total Stopping Distances