The National Highway Traffic Safety Administration Friday, July 24, issued a long-awaited regulation to tighten the stopping distance standards on heavy-duty tractors. The new standard generally requires that a tractor traveling at 60 miles per hour come to a complete stop within 250 feet when loaded to their gross vehicle weight rating (GVWR). The old standard required a complete stop within 355 feet.
For a small number of very heavy severe-service tractors, the stopping distance requirement will be 310 feet under these same conditions. And the final rule requires that all heavy truck tractors must stop within 235 feet when loaded to their “lightly loaded vehicle weight.”
Three-axle tractors with GVWRs of 59,600 pounds or less must meet the reduced stopping distance requirements by Aug. 1, 2011. Two-axle tractors and tractors with GVWRs above 59,600 pounds must meet requirements by Aug. 1, 2013. The requirements apply only to newly built tractors as of those dates.
Manufacturers can use any of several options to meet the requirement, including installation of enhanced drum brakes, air disc brakes or hybrid disc/drum systems, NHTSA says. The agency noted that a number of vehicles in the commercial fleet already use such braking systems and, therefore, already meet the requirements of the amended standard.
NHTSA estimates that the new braking requirement will save 227 lives annually and prevent 300 serious injuries. The agency also estimates that it will reduce property damage costs by more than $169 million a year.
For a copy of the NHTSA rule, click here.