The proposal, announced Aug. 26, discusses the benefits of setting the maximum speed at 60, 65, and 68 miles per hour but said a final rule could differ, depending on public input and vehicle tests to determine a speed limit for specific vehicle types.
Comments on the proposed rule will be accepted for 60 days after publication in the Federal Register. The rule wouldn't be effective until three years after the final rule is published in the register.
The joint proposal of the Federal Motor Carrier Safety Administration and National Highway Traffic Safety Administration said limiting the speeds of heavy vehicles will save lives and injuries, cut fuel costs and reduce greenhouse gases and other pollutants.
“This is basic physics,” NHTSA Administrator Mark Rosekind said in a statement. “Even small increases in speed have large effects on the force of impact. Setting the speed limit on heavy vehicles makes sense for safety and the environment.”
The proposal said that studies examining the relationship between travel speed and crash severity have concluded that the severity of a crash increases with increased travel speed. “Impact force during a crash is related to vehicle speed, and even small increases in speed have large effects on the force of impact,” the proposal said.
But rather than set a specific overall speed, NHTSA said it is proposing to establish new federal motor vehicle safety standards that would require new multipurpose passenger vehicles, trucks, buses, and school buses with a gross vehicle weight rating of more than 26,000 pounds to be equipped with a speed-limiting device. Additionally, as manufactured and sold, each vehicle would be required to have its device set to a specified speed and to participate in a vehicle-level test that involves the acceleration of the vehicle on a test track.
Motor carriers operating the vehicles in interstate commerce would be required to maintain the speed limiting devices for the service life of the vehicle, the proposal said.
Since this proposed rule would apply to both to vehicle manufacturers and motor carriers that purchase and operate these vehicles, the joint rulemaking is based on the authority of both NHTSA and FMCSA.
Although no specific speeds have been proposed, NHTSA said it has considered the benefits and costs of a 68-mph maximum set speed as requested in petitions filed in 2006 by American Trucking Associations and Road Safe America, as well as 60 mph and 65 mph maximum set speeds.
American Trucking Associations said the proposal is a “potential step forward for safety.”
“We are pleased NHTSA and FMCSA have, almost 10 years after we first petitioned them, released this proposal to mandate the electronic limiting of commercial vehicle speeds,” said ATA President Chris Spear. “Speed is a major contributor to truck accidents and by reducing speeds, we believe we can contribute to a reduction in accidents and fatalities on our highways.”
Although ATA recommended reducing the maximum speed to 68 mph in 2006, the federation in 2008 endorsed a national speed limit of no more than 65 mph for all vehicles.
However, the Owner-Operator Independent Drivers Association said the proposal would be dangerous for all highway users by creating speed differentials that could “lead to more crashes and promote road rage among other motorists.”
“Highways are safest when all vehicles travel at the same relative speed,” said OOIDA Executive Vice President Todd Spencer. “This wisdom has always been true and has not ever changed. No technology can replace the safest thing to put in a truck, which is a well-trained driver.”
The proposal estimates that limiting the speed of heavy vehicles to 60 mph would save 162 to 498 lives annually, limiting the speed of heavy vehicles to 65 mph would save 63 to 214 lives annually, and limiting the speed of heavy vehicles to 68 mph would save 27 to 96 lives annually. “Although we believe that the 60-mph alternative would result in additional safety benefits, we are not able to quantify the 60-mph alternative with the same confidence as the 65-mph and 68-mph alternatives,” the proposed rule said.
Based on range of fatalities prevented, the agencies said the rulemaking would prevent 179 to 551 serious injuries and 3,356 to 10,306 minor injuries with a maximum set speed of 60 mph, 70 to 236 serious injuries and 1,299 to 4,535 minor injuries with a maximum set speed of 65 mph, and 30 to 106 serious injuries and 560 to 1,987 minor injuries with a maximum set speed of 68 mph.
To reduce additional potential costs to vehicle manufacturers, NHTSA said it is not proposing requirements to prevent tampering or restrict adjusting the speed setting as part of its proposed vehicle safety standards.
Instead, to deter tampering with a vehicle’s speed-limiting device or modification of the set speed above the specified maximum set speed after the vehicle is sold, the proposed safety standards would require motor carriers to maintain the speed-limiting devices at a set speed, the proposal said.
“To assist FMCSA’s enforcement officials with post-installation inspections and investigations to ensure compliance with the requirement to maintain the speed limiters, NHTSA is proposing to require that the vehicle set speed and the speed determination parameters be readable through the On-Board Diagnostic connection,” the NPRM said.
In addition to reducing fatalities and injuries, the proposal projects that the rule would result in fuel savings and greenhouse-gas emissions reductions totaling of $848 million annually, assuming a 7% discount for fuel and a 3% discount rate for GHG, for 60-mph and 65-mph speed limiter settings.
“For 68-mph speed limiters, we would expect fuel savings and GHG emissions reductions to result in benefits of $376 million annually,” the proposal said.