Bendix Commercial Vehicle Systems VORAD DRIVER - Manual (Page 26)

Following Distance
Calculating Following Distance
One of the safest habits any driver can perform while operating a motor vehicle is
maintaining a minimum following distance from the other vehicles. Most commercial
vehicles traveling at a highway speed of 55 MPH require a minimum of 200 feet
or more to bring the vehicle to a complete stop on dry pavement. Conditions like
heavy loads, slippery roads, and worn tire tread can drastically increase a vehicle’s
stopping distance.
There are many factors that affect how quickly a driver can react to slowing or
stopping a vehicle. Every situation requires the driver’s best judgment. One driving
method that has been proven to reduce the likelihood of a front-end collision is
maintaining a following distance of no closer than three seconds.
Following distance is based on the speed of travel and the time to reach the
vehicle ahead should that vehicle come to a stop. You can use the formula below to
calculate following distance by fi rst converting road speed to feet per second.
55MPH = 290,400 Feet per Hour [5,280 x 55]
290,400 / 3,600 = 80.7 Feet per Second
Using the example above, a vehicle traveling 55 MPH would need to maintain a
minimum gap of approximately 242 feet from the vehicle ahead to maintain a
three-second following distance.
80.7 x 3 Sec. = 242.1 Feet
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