DOT plans speed limiters for large trucks

The National Highway Traffic Safety Administration and the Federal Motor Carrier Safety Administration are jointly proposing regulations that that would require vehicles with a gross vehicle weight rating (GVWR) of more than 26,000 pounds to be equipped with a speed limiting device. The regulations essentially would make motor carriers, not vehicle manufacturers, responsible for ensuring speed limiters remain set to the specified speed.

The notice of proposed rulemaking (NPRM) has not been published, but the text of the NPRM is available in draft form. Once published, interested parties will have 60 days to comment.

As proposed, the speed limiter initially would be set to a speed no greater than a speed to be specified in a final rule, and carriers operating those vehicles in interstate commerce would have to maintain those settings for the life of the vehicle. The agencies are floating three different speed limits – 60 mph, 65 mph and 68 mph – for public comment.

The speed limiter requirement would apply only to newly manufactured vehicles, but the agencies are considering whether to require retrofits or, alternatively, to require that commercial motor vehicles (CMVs) already equipped with speed limiting technology be regulated at the maximum speed.

NHTSA's proposed new federal motor vehicle safety standard (FMVSS) would require that each vehicle, as manufactured and sold, have its device set to a speed not greater than a specified speed and to be equipped with means of reading the vehicle’s current speed setting and the two previous speed settings (including the time and date the settings were changed) through its on-board diagnostic (OBD) connection.

In order to avoid excessive costs on vehicle manufacturers, however, NHTSA's proposed FMVSS would not require that speed limiters be tamper-proof or tamper-resistant to prevent adjustments after they are manufactured and sold. Instead, FMCSA proposes a related regulation that would require each CMV with a GVWR of more than 26,000 pounds to be equipped with a speed limiting device meeting the requirements of the proposed FMVSS applicable to the vehicle at the time of manufacture. Carriers would be required to operate the devices set to a speed not greater than the specified speed for the service life of the vehicle.

The Senate-passed version of the fiscal 2017 appropriations bill would mandate a final rule on speed limiters within six months of the bill's enactment. The House version does not include a similar provision, and it's possible that the legislation will not be finalized until December.

Costs and benefits

The agencies' estimated costs and benefits vary based on regulatory assumptions and the speed setting chosen among 60 mph, 65 mph and 68 mph. There is no assumed cost for the devices themselves since they are integrated into engine electronics, but the agencies did project costs ranging from $206 million a year to $1.534 billion a year associated with increased delivery times.

Offsetting those costs were safety and fuel saving benefits ranging from $684 million to $6.522 billion. In addition to greater benefits for lower speeds, the fuel savings vary depending on whether current vehicle fuel economy/greenhouse gas (GHG) reduction rules remain in place or NHTSA and the Environmental Protection Agency's recently finalized phase 2 GHG reduction rules take effect. Assuming the rules are not overturned by Congress, the courts or a future administration, the benefits of speed limiters would be reduced because the GHG rules would lower fuel use.

Given those assumptions, NHTSA and FMCSA estimate net annual benefits of $475 million to $4.964 billion.