Stopping Distances Slashed by New US Braking Standards

On July 24 the US based National Highway Traffic Safety Administration announced new braking standards that will require the “vast majority” of heavy truck tractor units to achieve a 30 per cent reduction in stopping distances compared with current levels. The new regulation, which will be phased in over a four year period beginning with 2012 models, sets out that these vehicles should be capable of stopping from sixty miles per hour in not more than 250 feet when loaded to their gross vehicle weight rating. Previous standards required a complete stop within 355 feet. When lightly loaded, the stopping distance from sixty miles per hour should be within 235 feet.

The purpose of these amendments, says the NHTSA, is to reduce the number of fatalities and injuries associated with crashes involving tractor-trailer combinations and other vehicles. The NHTSA estimates that the new braking requirement will save 227 lives annually, and will also prevent 300 serious injuries. In addition, this rule is expected to prevent over US$169 million in property damage annually, an amount which alone is anticipated to exceed the rule’s total cost.

“Safety is our highest priority,” NHTSA secretary LaHood said. “Motorists deserve to know they are sharing the road with large trucks that are up to the safest possible standards, so they can get home alive to their families.”

The NHTSA notes there are “a number of simple and effective manufacturing solutions” vehicle manufacturers can use to meet the requirements of this final rule. These include the installation of enhanced drum brakes, air disc brakes, or hybrid disc/drum systems. Some vehicles already in the US commercial fleet already utilise these improved braking systems and realise performance that would meet the requirements of the amended standard. The new rule applies only to truck tractors, and does not include single-unit trucks, trailers and buses.