The US Department of Transportation and the National Highway Traffic Safety Administration released a new proposal Friday to require heavy-duty vehicles like trucks and buses to include speed-limiting devices. If approved, all newly manufactured trucks, buses, and passenger vehicles weighing more than 26,000 pounds would be required to come equipped with devices limiting their speeds to 60–68 mph. That would cover big rigs, dump trucks, refuse haulers, many buses, and other large work trucks.

The new rule is being touted by the feds as an important step toward fighting the rise in traffic fatalities across the country, as well as a key ingredient in lowering CO2 emissions. "In addition to saving lives, the projected fuel and emissions savings make this proposal a win for safety, energy conservation, and our environment," DOT secretary Anthony Foxx said in a statement.

"a win for safety, energy conservation, and our environment"

Safety advocates note that research shows speed to be a crucial factor in nearly a quarter of all truck crashes. Since 1992 all trucks in the US have been manufactured with the speed-limiting equipment, but the trucking industry has resisted calls to "flip the switch" to activate this technology. "Speed limiters are an available solution to large trucks flagrantly exceeding highway speed limits and needlessly putting the public at grave risk," said Henry Jasny, senior vice president and general counsel for the Advocates For Highway and Auto Safety.

Perhaps surprisingly, the trucking industry is in support of the new mandate. "We know the cliché ‘speed kills’ is true when it comes to driving," Sean McNally, spokesman for the American Trucking Associations (ATA), told Trucks.com. "Speed is a factor in a third of all vehicle crashes and 23 percent of all truck crashes, so slowing our vehicles down can have tremendous safety benefits."

The ATA has urged safety regulators to limit the speed of all vehicles, including passenger cars, to 65 mph. But safety groups want the speed capped at 60 mph.