NEW BRAKING standards for commercial truck tractors were issued in July and will be phased in over four years. Issued by the National Highway Traffic Safety Administration (NHTSA), the new standard cuts the truck stopping distance by roughly 30%.
The long-awaited braking standard mandates tractor-trailers traveling at 60 miles per hour must come to a complete stop in 250 feet, versus the old standard of 355 feet.
For a small number of very heavy severe-service tractors, the stopping distance requirement will be 310 feet under these same conditions, according to NHTSA. In addition, this final rule requires that all heavy-duty truck tractors must stop within 235 feet when loaded to their lightly loaded vehicle weight (LLVW).
Though this new regulation is going to be phased in over four years beginning with 2012 models, NHTSA said three-axle tractors with a gross vehicle weight rating (GVWR) of 59,600 pounds or less must meet the reduced stopping distance requirements specified in this final rule by August 1, 2011.
Two-axle tractors and tractors with a GVWR above 59,600 pounds must meet the reduced stopping distance requirements specified in this final rule by August 1, 2013, the agency noted, adding that voluntary early compliance is allowed.
NHTSA stresses that this new rule applies only to truck tractors and does not impact single-unit trucks, trailers and buses. The rule change has been in the works since 2005.
Importantly, the new rule comes with no retrofit requirement. Trucks built to the old standard will not have to be retrofitted with the new brakes.
Manufacturers should be able to meet the requirements of the new rule with existing truck brake technology, according to NHTSA officials. There was speculation that tighter performance standards might force a switch to air-disc brakes from drum brakes.
NHTSA estimates that the new braking requirement will save 227 lives and prevent 300 serious injuries annually, while reducing property damage costs by over $169 million on a yearly basis, an amount which alone is expected to exceed the total cost of the rule, the agency points out.