Speed-Limiter Rule: What Are Even The Options?

Will ECUs actually work to limit speeds in CMVs? Speed limiter rule.

Implementing speed limiters is not the most important discussion point. The question is, will the proposed regulation actually achieve what it is intended to do?

We have all heard about it by now.

The Federal Motor Carrier Safety Administration’s (FMCSA) has released a notice of intent to proceed with rulemaking to mandate speed limiters on most heavy-duty trucks, restarting a process that had been dormant for six years. 

In fact, a speed limiter mandate has been delayed by the federal government more than 20 times since it was first proposed in 2011.

Right now, there is no suggestion on what the speed-limiter should be set for, such as 65mph, 68 mph, or 75mph and, if a rule is submitted, we will likely not see it affect drivers until 2024-2026.

The only consensus is most large-truck equipment manufacturers already added the technology needed for speed-limiters to become a reality since OEMs have been installing electronic engine control units (ECUs) in CMVs since 2003.

With this in mind, let’s discuss what the arguments are around speed-limiters and what choices you have when commenting on the proposed rulemaking.

FMCSA says safety is their priority

This is common knowledge by now, especially as safety was force fed to us when the electronic logging device (ELD) mandate was being discussed.

“The number of commercial motor vehicle (CMV) crashes in which speed is listed as a contributing factor is unacceptable,” FMCSA stated.

So, what are the statistics?

A previous FMCSA study found that trucks not using their speed limiters had a 200 percent higher highway-speed crash rate compared to trucks using speed limiters.

Based on the agencies’ review of the available data, limiting the speed of these heavy vehicles would reduce the severity of crashes involving these vehicles and reduce the resulting fatalities and injuries. 

They estimate that limiting heavy vehicles to 68 mph would:

  • save 27 to 96 lives annually
  • prevent 30 to 106 serious injuries and 560 to 1,987 minor injuries

They estimate that limiting heavy vehicles to 65 mph would:

  • save 63 to 214 lives annually
  • prevent 70 to 236 serious injuries and 1,299 to 4,535 minor injuries

The NHTSA came up with these numbers by looking at crash data from 2004-2013 where only cases in which both the speed of the heavy vehicle likely affected the severity of the crash over 55mph. There were 11,056 heavy vehicles involved in fatal crashes, which were then used with heavy vehicle travel speed data to estimate the number of fatal crashes at various travel speeds.

The FMCSA says that a rule focused on ECUs limiting speed would be a quick way to prevent the lives lost or injuries from a crash.

The other added benefit is FMCSA expects that 68 mph speed limiters would improve fuel savings and GHG emissions reductions to result in benefits of $376 million annually, which seems inaccurate if you consider the smaller cars backed up behind semi’s trying to pass each other or cars accelerating past the slower than flow of traffic truckers.

Highways are safest when all vehicles travel at the same relative speed

The problem with the safety analysis is that highways are safest when all vehicles (including smaller cars and trucks) travel at the same relative speed.

In other words, if nationwide speed limits were set for both cars and trucks at 65 mph, and semi-trucks were limited to 65mph, then the safety argument would make sense.

However, the national trend on roadway speed limits is moving in the opposite direction as many states relax strict speeds on highways.

The American Trucking Associations (ATA), which advocates for larger carriers, has supported requiring speed limiters set at 65 mph for trucks built after 1992 – but only if nationwide speed limits for both cars and trucks are set at 65 mph as well.

This seems unlikely to happen, thus the speed gap between large and small vehicle will make the roads more unsafe if a speed-limiter rule was to happen.

Will ECUs actually work to limit speeds in CMVs?

Lastly, let’s quickly discuss the ECU argument as well.

“It is likely the required means of achieving compliance with a speed limiter requirement would be to use the ECU to govern the speed of the vehicle rather than installing a mechanical means of doing so,” FMCSA wrote in its notice last week. 

But will ECU speed limiters work? Do we have an example that can show us what is likely to come in the U.S.?

Actually, we do… Canada.

Since 2008, most trucks operating in Ontario and Quebec have been required to have their maximum road speed mechanically limited to 105 km/h.

In late 2019, Burness Paralegal Services, based out of Thamesford, Ont., prepared to challenge the reliability of the after-market plug-in enforcement measurement device on behalf of a U.S. fleet that was charged with non-compliance of the speed limiter rule in April 2018. The truck – a 2014 Freightliner with Detroit Diesel engine – was examined at the Sarnia inspection facility and found to have its speed limiter set to 116 km/h.

In other words, OEMs have messed up programing on trucks and had to pay for reprogramming tow bills etc.

In fact, roadside enforcement isn’t even checking trucks regularly because too many trucking companies took them to court over messing up ECU programming on trucks.

Different manufacturers have different methods of limiting speed and use as many as 15 parameters to limit maximum road speed under different conditions.

Engine manufacturers are also inconsistent in the naming of the required setting. For example, the Cummins parameter is referred to as the Accelerator Maximum Vehicle Speed, while Detroit Diesel calls it the Max Road Speed.

These issues would need to be discussed in detail before a rulemaking can even be considered in the U.S.

What is next for the Speed-Limiter Rule?

There was a 30-day period for public comments (which nearly 6,000 comments have been submitted thus far) and data regarding the adjustment or reprogramming of ECUs. The comment period was extended and is now open through July 18.

FMCSA will consider the information obtained through the Notice of Intent comments and anticipates publishing the Supplemental Notice of Proposed Rulemaking (SNPRM) sometime in 2023. The rulemaking requires the Office of Management and Budget review before publication.

If a rule is submitted, we will likely not see it affect drivers until 2024-2026 at the earliest.

To submit your comment online, go to https://www.regulations.gov/document/FMCSA-2022-0004-0001, click on this NOI, click “Comment,” and type your comment into the text box on the following screen.

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