A proposal to limit the speed of heavy trucks to 65 mph proposed earlier this year by truck safety groups has been taken up by two U.S. Senators.

“The Cullum Owings Large Truck Safe Operating Speed Act of 2019,” introduced on June 27 by Johnny Isakson (R-Georgia) and Chris Coons (D-Delaware), would require new commercial trucks weighing over 26,000 pounds to be equipped with speed limiters set at a maximum speed of 65 miles per hour. Existing trucks that already have the technology installed would be required to set the 65-mph limit as well, while those without speed limiters would not be required to install the technology retroactively.

“The majority of trucks on our roads already have speed-limiting technology built in, and the rest of the technologically advanced world has already put them to use to ensure drivers follow safe speeds,” Isakson said. “This legislation would officially enforce a long-awaited speed limit of 65 mph on large trucks and reduce the number of preventable fatalities on our busy roadways.”

The legislation comes five months after a coalition led by Road Safe America and the Truck Safety Coalition began lobbying Congress on the issue after previous attempts at changing the law stalled.

“Once we learned that this technology, which could have saved our son, was available and in use by many leading U.S. companies, we founded Road Safe America to educate the public and change things like this,” said Road Safe America president and co-founder Steve Owings.

“This critical safety measure, which has languished for more than 10 years, will put an end to the practice of protecting companies that rely on speeding to remain competitive,” said Harry Adler, executive director of the Truck Safety Coalition.

While it didn’t participate directly in the lobbying effort as part of the Truck Safety Coalition, the Trucking Alliance, whose members include major truckload carriers such as J.B. Hunt (NASDAQ: JBHT), U.S. Xpress [NYSE: USX] and Knight-Swift Transportation (NYSE: KNX), is a proponent of speed limiters and supports the legislation.

“We’re confident Congress will pass this bill and help reduce large truck crashes in which more than 140,000 people were killed or injured last year,” said Trucking Alliance managing director Lane Kidd.

The American Trucking Associations (ATA), has supported speed limiters for both cars and trucks, said it was reviewing the details of the bill. “Our policies support speed limiters but were adopted in the context of more uniform national speed limits for all vehicles,” an ATA spokesman told FreightWaves. “As the national trend on speed limits moves in the opposite direction with increasing variance, federal speed limiter efforts must at a minimum account for speed differentials and any potential safety risks that they can create.”

The Owner-Operator Independent Drivers Association told FreightWaves it opposes the speed limiter mandate, claiming speed limiters will not reduce crashes because most truck-related crashes occur on roads with posted speeds less than 65 mph. “To improve highway safety, we support minimum training standards that include behind the wheel time and flexibility in hours of service regulations.”

Supporters of the bill point out that a speed limiter mandate has been delayed by the federal government more than 20 times since it was first proposed in 2011. A comment period on a proposed rule from the Federal Motor Carrier Safety Administration – which as written would only apply to new trucks – ended in November 2016, but no final action has been taken.

A speed limiter mandate was recently added to the most recent effort to raise the national standard for twin trailers from 28 to 33 feet as a safety incentive to gain support from lawmakers and safety advocates for increasing truck-hauling capacity.

The latest “twin 33” proposal, led by the Americans for Modern Transportation Coalition, would require that twin 33s be equipped with speed limiters set at 68 mph, along with on-board video event recorders, electronic stability control and automatic emergency braking.