The Importance of Total Stopping Distance

An 80,000 pound, fully-loaded semi can weigh 20 times more than an average car or truck. Even with terrific braking systems, trucks simply can’t stop as quickly as passenger vehicles.

A vast majority of the information you gather while driving is received through your vision, such as the cars around you, traffic signals, street signs, road construction, pedestrians, and much more. While your sense of sight is crucial, it’s also important to rely on your driver training.

Do you know how to come to a complete stop safely and swiftly to avoid injury? Do you recall what contributes to Total Stopping Distance?

The large nature of commercial vehicles makes them a potentially dangerous object on the roadway, and drivers much take stopping distance into consideration. A normal passenger vehicle will take approximately 316 ft. to come to a complete stop after recognizing the need to stop, versus a semi-truck that takes around 525 ft; about two football fields.

Total Stopping Distance is the sum of Perception Distance, Reaction Distance, and Braking Distance.

Total Stopping Distance is the distance your vehicle travels from the time your brain recognizes the need to stop until your vehicle comes to a complete stop. Although it is primarily made up of the three tangible factors above, there are additional variables and factors that impact the time it takes for a truck to come to a complete stop.

Due to the height drivers sit in a truck, there is a potential for faster recognition of hazards that a passenger vehicle driver has not yet seen. Commercial Drivers should look about 12-15 seconds ahead for upcoming hazards and other reasons to stop. Icy, wet road conditions also dramatically impact braking stance. Also, since truck brakes are designed for a truck carrying a full load, an empty truck will take longer to stop than a full one.

PERCEPTION DISTANCE

The distance your vehicle travels from the time you see a hazard until your brain recognizes the hazard. For an alert driver, this is about 3/4 second. At 55 mph, a driver will travel 60 ft in that amount of time

REACTION DISTANCE

The distance your vehicle travels from the time your brain orders your foot to brake until your foot is actually touching the brake. Also, 3/4 second, add 1/2 second for air brakes.

BRAKING DISTANCE

The distance your vehicle travels from the time you activate your brakes to when the vehicle stops. At 55 mph, this is about 4.5 seconds or 170 ft.