Semi Trucks Must Keep a Safe Following Distance to Avoid an Accident
We have all heard of serious injury accidents occurring because a vehicle is following another vehicle too closely and is unable to stop in time. The danger is heightened when the following vehicle is a semi truck because its size and weight make it more difficult to stop quickly and the subsequent damage from an accident is often much greater.
When a semi truck driver is going to stop a vehicle to avoid an accident, he/she must go through a few steps first. The driver must perceive the hazard and then decide what to do. The more fatigued a driver is, for instance a semi truck driver who has been on the road for hours, the longer this perception and decision time takes. After the decision to stop is made, there is physical reaction time where the driver has to put his/her decision to stop into action. Once the semi truck driver puts his/her foot on the brakes, the air brakes on a semi truck lag for a short period of time to allow the brakes to obtain the air they need. Semi truck brakes typically do not operate as quickly as regular passenger cars. This delay is approximately 1/2 of a second, but at a speed of 65 miles per hour, the delay could mean an extra 50 feet before the semi truck begins to stop. Once the brakes are applied, friction begins to slow the vehicle to a stop. The weight and speed of the vehicle along with any road conditions (water, ice, etc.) can prolong this process.
At normal highway speeds, a semi truck may take approximately 300 feet to stop to avoid an injury accident from the time the semi truck driver perceives the hazard. If the semi truck is following a vehicle closely, there is a good chance there will not be enough room or time to stop without causing an accident. As a result, semi trucks should leave more distance from the vehicle in front of them than regular cars. It is recommended that semi trucks stay one second behind the vehicle in front of them for every ten feet of vehicle plus an extra second if driving more than 40 miles per hour.
