NHTSA Issues Rule to Cut Truck Stopping Distance by 30%
By Sean McNally, Senior Reporter
This story appears in the July 27 print edition of Transport Topics.
The National Highway Traffic Safety Administration will require a cut of 30% in the allowable stopping distance for the majority of new trucks beginning in 2011, the agency said Friday.
“For these heavy truck tractors — approximately 99% of the fleet — the amended standard requires those vehicles to stop in not more than 250 feet when loaded to their gross vehicle weight rating and tested at a speed of 60 miles per hour,” the rule states.
Currently, trucks must make that stop within 355 feet.
In an accompanying statement, Transportation Secretary Ray 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 rule will require heavy tractors to stop within 235 feet when at their lightly loaded vehicle weight — the weight of the unloaded vehicle plus 396 pounds for the driver and instruments.
NHTSA, in the rule, said three-axle tractors weighing less than 59,600 pounds must meet the new stopping distance by Aug. 1, 2011, and two-axle tractors and tractors weighing 59,600 pounds or more must meet the new standard by Aug. 1, 2013.
NHTSA said the rule “applies only to truck tractors, and does not include single-unit trucks, trailers and buses.” In addition, “a very small number of very heavy severe service tractors” will have their stopping distance limit cut to 310 feet.
The agency first proposed reducing the stopping distance of large trucks in December 2005, saying it was looking at trimming stopping distances by between 20% and 30%.
The new rule, first proposed in 2005, was nearly finalized during the waning days of the Bush administration, but was pulled back from the White House Office of Management and Budget late last year for further review. That delay was the most recent in a series of holdups in publishing the rule, which had been promised by NHTSA officials as far back as 2007.
In the rule, NHTSA said the improved braking performance would “reduce the number of fatalities and injuries associated with crashes involving tractor-trailer combinations and other vehicles . . . [and] will prevent a substantial amount of property damage through averting or lessening the severity of crashes.”
The agency estimated that once all trucks on the road are equipped with brakes capable of meeting the new standard “approximately 227 lives will be saved and 300 serious injuries will be prevented” each year.
“This final rule is expected to prevent over $169 million in property damage annually, an amount which alone is expected to exceed the total cost of the rule,” NHTSA said.
During the run-up to the final rule, there was speculation the tighter standards might require a change in technology to air-disc brakes from the drum brakes.
However, industry officials have said they anticipate being able to meet the standard with existing technology, a position endorsed by NHTSA.
“There are a number of simple and effective manufacturing solutions that vehicle manufacturers can use to meet the requirements of this final rule . . . [including] installation of enhanced drum brakes, air disc brakes, or hybrid disc/drum systems,” the agency said. “We note that currently a number of vehicles in the commercial fleet already utilize these improved braking systems and already realize performance that would meet the requirements of the amended standard.”
