After avoiding congressional leaders’ attention for several years, speed limiters on trucks are receiving renewed interest on Capitol Hill.

House members Lucy McBath (D-GA) and John Katko (R-NY) recently reintroduced the “Cullum Owings Large Truck Safe Operating Speed Act.” The legislation would mandate U.S. Transportation Department (USDOT) regulations requiring speed limiters on all new commercial motor vehicles (CMVs), and speed limiting technologies already installed on CMVs manufactured after 1992.

Speed limiters would keep CMVs under 65 mph. Trucks equipped with adaptive cruise control systems and automatic emergency braking systems could travel at a maximum speed of 70 mph. The “Cullum Owings Large Truck Safe Operating Speed Act” is named for the deceased son of the founder of Road Safe America, killed in a car-truck crash.

Senator Chris Coons (D-DE) and former Sen. Johnny Isakson (R-GA) introduced the same legislation in 2019. But the issue of speed limiters, or speed governors as they are sometimes referred to, has a longer history:

  • In 1991, the National Highway Traffic Safety Administration (NHTSA) issued a report to Congress on CMV speed control devices. While NHTSA supported efforts to reduce truck speeds, it did not conclude that speed limiters should be required, citing uncertainty of when speeding itself was the primary cause of an accident.
  • In 2006, the American Trucking Associations (ATA) petitioned NHTSA and the Federal Motor Carrier Safety Administration (FMCSA) for rulemakings requiring speed limiters on new trucks and prohibiting motor carriers and drivers from adjusting the devices to speeds higher than 68 mph.
  • At the same time, Road Safe America, a public safety interest group, and a group of nine motor carriers, petitioned FMCSA for speed governors on all trucks manufactured after 1990, with the maximum speed set at 68 mph.
  • Ten years later, NHTSA and FMCSA discussed these petitions in a 2016 joint rulemaking seeking comments on speed limiters set at 60, 65 and 68 mph. The rulemaking dismissed the 1991 NHTSA report by noting that technology which would support speed limiters had become standard on all CMVs. FMCSA also pointed to a 2012 study, finding “profound safety benefits” from speed limiter use. The joint NHTSA/FMCSA rulemaking died quietly, a casualty of changing White House administrations.

Today, ATA and Road Safe America have again appealed to USDOT for guidelines on speed limiters. Both groups note the growing use of driver-assist technologies, such as adaptive cruise control systems and automatic emergency braking systems, in addition to speed limiters, as part of a holistic approach to safety management. The “DRIVE-Safe Act” legislation includes all three technologies.

Many motor carriers currently use speed governors to save fuel and reduce maintenance costs, as well as for safety. However, the Owner-Operator Independent Drivers Association challenges the safety benefit of speed limiters. The group argues the devices can create unsafe speed differentials in traffic and limit a truck driver’s ability to safely pass or to accommodate vehicles merging onto the highway.

Speed limits have long been part of a national debate. The national maximum speed limit was 55 mph in 1974, raised to 65 mph in 1987 and 1988, and repealed at the federal level in 1995. The speed limiter debate will likewise continue.

The provisions mentioned here could find their way into the comprehensive infrastructure packages under consideration in either the House or Senate. Proponents and opponents of speed limiters may well square off instead, before NHTSA and FMCSA, should those agencies again announce a speed limiter rulemaking. Many government-watchdogs believe with the change in administrations this year, one or both of these agencies will likely move forward with a speed limiter proposal, even if Congress doesn’t take action.