FMCSA and NHTSA Withdraw the Heavy-Truck Speed Limiter Plan

In July 2025, the Federal Motor Carrier Safety Administration (FMCSA) and the National Highway Traffic Safety Administration (NHTSA) formally dropped the plan to require speed limiters on heavy trucks. A notice published on July 24, 2025 withdrew two rulemaking documents that had been pending for years.

What was withdrawn

The first was the joint NPRM of September 7, 2016. It proposed that vehicles with a gross vehicle weight rating of more than 26,000 pounds be equipped with a speed limiting device kept at a set speed. The proposal analyzed three possible settings: 60, 65 and 68 mph. The agencies received 7,225 comments by the December 7, 2016 deadline. Among commenters who named a preferred speed, the choice was split nearly evenly among the three.

The second was FMCSA's advance supplemental notice of May 4, 2022. It said the agency intended to propose that motor carriers limit the speed of certain interstate trucks already equipped with an electronic engine control unit (ECU) capable of setting a maximum speed, and keep that limit for the life of the vehicle. That notice drew 15,638 comments. FMCSA said about 300 of them expressed some support for moving ahead.

Why the agencies pulled back

The agencies said the 2016 proposal lacked "a sufficiently clear and compelling safety justification" and raised significant concerns about federalism. They said their research had significant data gaps on safety benefits and economic impacts, and that public comments did not supply what was needed to reach a final rule. FMCSA withdrew the 2022 notice for the same reasons.

The notice set out several specific problems:

• Uncertain baseline. Crash-avoidance technology such as automatic emergency braking and forward collision warning could reduce some of the rear-end crashes the speed limiter rule was expected to prevent. This made the expected safety benefit hard to measure.
• Crashes not estimated. The 2016 proposal did not estimate crashes avoided or caused, and it remained unclear whether it would increase crashes such as light vehicles striking the rear of speed-limited trucks.
• Speed differentials. The most common concern among drivers who opposed the plan was the gap in speed between limited trucks and cars.
• State authority. The speeds under consideration were below the posted daytime limits on many roads, including rural Interstates in more than half of the states. The agencies said the rule could, over time, have displaced state authority to set truck speed limits.