NHTSA seeks faster-stopping tractors

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The National Highway Traffic Safety Administration has proposed to reduce the required stopping distance for truck tractors equipped with air brakes by 20 to 30 percent, but the agency believes that the technology for achieving this performance exists today. And given that vehicles produced today are able to comply with proposed reductions in stopping distance by only modifying foundation brakes, NHTSA is proposing that truck makers comply within two years of a final rule.

While improved technologies like air disc brakes and electronically controlled braking are available, NHTSA says its research indicates that tractors would be able to comply with its proposed reduction in stopping distance through use of larger drum brakes. NHTSA estimates that 3 percent of existing tractors already comply with a 30 percent improvement versus the minimum standard.

A 20 percent improvement in braking performance would save an estimated 104 lives, while a 30 percent improvement is projected to save 257 lives, NHTSA said. Improvements of 20 to 30 percent also would reduce property damage by $32 million or $166 million, respectively.

Potential compliance costs depend on whether truck manufacturers chose larger S-cam drum brakes or more expensive disc brakes, NHTSA said. The agency estimates that a 20 percent reduction in stopping distance would cost the industry $14 million to $119 million, while a 30 percent reduction would range from $20 million to $170 million.

Weighing costs and benefits, a 20 percent reduction would produce net benefits of $320 million to $425 million, NHTSA said. A 30 percent reduction would produce net benefits of $994 million to $1.144 billion.

NHTSA is still considering changes to the required stopping performance of single unit trucks and buses using air brakes and of hydraulically braked vehicles over 10,000 lbs. GVWR and will address those following relevant ongoing research.

Comments on NHTSA’s notice of proposed rulemaking, which the agency says is based on current safety trend data and brake system technologies, are due April 14. For a copy of the NPRM, visit http://dms.dot.gov/search and search Docket No. 21462.