The issue of speed limiters in commercial trucks is one of the most drawn-out debates in the trucking industry. The seemingly never-ending loops of announcements, comments, and expected rulings make it into the headlines now and then.

So let’s try to understand the issue: what is a speed limiter, who likes them, who doesn’t, and what does the data say about their effectiveness in trucking?

What is a speed limiter?

A speed limiter is a safety device that – you guessed it – limits the speed of a vehicle.

It uses sensors to detect how fast the vehicle moves and sends the information to the engine’s computer. The computer can then restrict fuel and air flow to the engine so that the driver can’t exceed the maximum speed.

The Fraught History of Speed Limiter Policy

Many large fleets already use speed limiters, mainly to improve safety and fuel efficiency, but the federal government has never mandated them.

The idea of mandating speed limiters in commercial fleets first came from a study conducted by the National Highway Traffic Safety Administration in 1991. In that first report, the NHTSA hadn’t found enough evidence to justify mandating speed limiters.

Fast-forward fifteen years to 2006 and a lot had changed. There was better data available on crash statistics and the cost of speed limiter technology had come down significantly.

The American Trucking Associations (ATA) petitioned the NHTSA to require truck manufacturers to include speed limiters in vehicles weighing more than 26,000 pounds.

They proposed limiting speed to no more than 68 miles per hour and including a regulation that would prohibit drivers from adjusting the speed limiters. Road Safe America made a similar petition the same year.

Since then, the NHTSA and FMCSA have commissioned multiple reports and rounds of public comments on the issue. In a study reviewing data from 2004 to 2013, the agencies found that crashes involving vehicles weighing over 26,000 pounds where speed was a significant factor resulted in over 10,000 deaths.

Despite multiple attempts to revisit the issue over the years, the FMCSA has been unable to make a final ruling on how to implement speed limiters.

The most recent development happened in September of 2023 when the FMCSA announced that the rule would require trucks weighing more than 26,000 to install speed limiters. They cited that the maximum speed could be set to 68 miles per hour.

However, the FMCSA missed its December 29, 2023 deadline for issuing the ruling. It’s still unclear how long it will take to issue the policy and when it will go into effect. It’s unlikely the implementation of the ruling would happen before 2025.

Who Supports Speed Limiters and Why?

Industry organizations representing large carriers support a speed limiter mandate in some form, including the ATA, the Truckload Carriers Association (TCA), the Truck Safety Coalition, and the Alliance for Driver Safety & Security. The ATA has come out in favor of a 65-70 mph maximum speed, depending on other safety technology in place in the vehicle, while safety groups support 60 mph.

In a survey conducted by TCA, all but one carrier reported that their fleets already use speed limiters. The majority of fleets said they set limiters in the upper 60s. Carriers using speed limiters cite additional benefits to safety and fuel efficiency.

Groups in favor of a speed limiter mandate believe that driving over 60-70 mph puts the driver and others on the roadway at risk of more collisions and fatalities. Driving too fast for conditions is indeed a major risk factor for crashes.

But is it as simple as capping the maximum speed on roadways?

Who’s Against Speed Limiters and Why?

Many truck drivers oppose mandatory speed limiters due to concerns about increasing pressures for on-time deliveries and a loss of control of trucks in dangerous situations. The sheer volume of comments the FMCSA received from truckers opposing the speed limiter ruling has been a major factor in delaying the new policy.

Groups backing drivers’ concerns include Republican lawmakers, the Owner-Operator Independent Drivers Association (OOIDA), the American Farm Bureau Federation, the National Cattlemen’s Beef Association, the U.S. Cattlemen’s Association, the Livestock Marketing Association, and the National Association of Small Trucking Companies (NASTC). Some of these organizations have sponsored legislation that would limit the FMCSA’s ability to make speed limiters mandatory.

According to one Republican lawmaker, a speed limiter mandate would lead to more dangerous driving because drivers would need to make up for lost time on city streets, suburbs, and construction zones. Speed limiters wouldn’t make a difference in these areas where the speed limit is already below 60 mph.

Others argue that forcing trucks to drive slower than the flow of traffic could also cause more crashes.

What Does the Data Say?

Most of what you read about this issue tends to focus on individual accounts and preferences or hypothetical scenarios. But how effective are these devices, actually?

A study conducted by the USDOT in 2012, including data from about 138,000 trucks showed positive benefits for speed-limited trucks. Trucks equipped with speed limiters had a “statistically significant lower speed-limited-relevant crash rate compared to trucks without speed limiting devices. (1.6 crashes per 100 trucks/year versus 2.9 crashes per 100 trucks/year).”

Many leading countries, including Japan, Australia, and European Union members, have introduced speed limiter mandates for trucks.

In 2009, speed limiter mandates went into effect in Quebec and Ontario, capping the speed of large trucks at 105 km/hour, or about 65 mph. A study by the Ontario (Canada) Ministry of Transportation found a significant decrease in the number of crashes and fatalities involving large trucks where speed was the main factor in the three years following the implementation of the speed limiter mandate. The researchers couldn’t find evidence that slower speeds on faster roadways resulted in more speeding in lower-speed areas.

As much as most truck drivers won’t like a speed limiter mandate, the evidence that it would reduce crashes and fatalities is pretty convincing. But this won’t be the only effect. The US trucking industry is a unique one and we won’t be able to predict all the possible consequences of a speed limiter policy until it happens.

For more updates on FMCSA rulings and to make your voice heard on this topic, visit the FMCSA Regulatory Guidance portal.

Of course, we hope it never happens, but every truck driver and trucking business owner should have a plan in place in case of an accident on the road. Learn what to do in case of a crash in this article.