Speed Limiters

Speed limiters, also described as speed governors, are devices that interact with a truck engine to permit the attainment of a pre-programmed maximum speed.  Speed limiters are electronic controlled modules (ECM) that are capable of limiting the maximum speed. 

The Federal Motor Carrier Safety Administration, safety groups, and large carriers have been pushing for a speed limiter mandate on commercial motor vehicle for years because of proposed safety benefits.  In response, FMCSA gave a contract to a company called MainWay Services to conduct research on the safety benefits of speed limiters.  In December 2010, FMCSA released their findings in a "draft final report."  The report however did not support any safety benefits stating, "because of data limitations and data quality, the research team could not definitively attribute the effect to the presence of an active (speed limiter)."

The results evidently were not what FMCSA anticipated and another "final report" came out in 2012. The two reports are almost identical, except for a few omissions and rephrasing of words.  All of the research and data remained the same, but the interpretation was changed from, the data did not support speed limiters, to "The findings showed strong positive benefits for SLs (speed limiters)."  However, Steven L. Johnson, a professor at the University of Arkansas and one of the co-authors of the original final draft, wrote a white paper demonstrating a number of limitations of the report's findings.  Johnson concluded that the data utilized in FMCSA's study did not find a statistical significance in reduction of crashes due to speed limiters.

FMCSA, safety groups, and large carriers often proclaim the so-called safety benefits of speed limiters, but yet they refuse to look at the real-world facts, even in their own study.  The American Trucking Association, which is formed primarily of large carriers, states that reducing speed-related crashes involving trucks is critical to NHTSA's and FMCSA's safety missions.  Nonetheless, it is a fact that most large carriers, which constitute only 1% of all motor carriers, have already invested in speed limiters and desire to force small carriers to invest also.

OOIDA is opposed to a mandate for speed limiters, as mandating speed limiters would decrease overall highway safety because the interaction between large trucks and passenger vehicles would increase.  It is important to note that there is no clear evidence that supports that the use of speed limiters will improve safety.  In fact, there is data that states that high-speed related truck crashes are rare events and the reduction of speed and power can have negative effects on safety.

Studies have demonstrated that a higher variance of vehicle speeds in traffic flow increases the risk of an accident, and speed limiters cause speed variance.  Regardless of the average speed on the highway, the greater a driver deviates from the average speed, the greater his chances of being involved in an accident.  Low speed drivers are more likely to be involved in accidents than high-speed drivers are.  In 80 percent of rear-end collisions involving a large truck and a car resulting in a fatality, the passenger vehicle rear-ended the truck.

Furthermore, a reduction in speed will cause more congestion.  Other vehicles will have to decelerate and then accelerate to maneuver around the slower traffic; this will increase fuel consumption and increase safety concerns. 

In addition to decreased safety concerns, many argue that a speed limiter mandate would not address one of the top causes of large truck crashes, traveling too fast for conditions.  While it is true that speed is a factor in some crashes, it is mixed in terms of the relationships of speed to the speed limits.  The data showing crashes that occur when the vehicle was traveling above the speed limit is minor compared to the case of traveling too fast for conditions.

"As cited in Office of Motor Carrier Safety 1999, up to 21 percent of fatal large truck crashes included the attribute of speeding," with speeding being defined as going too fast for conditions.  The core issue appears to be crash risk relating to speed limit compliance versus absolute speed.  For instance, a NHTSA study found that a much higher percentage of drivers involved in crashes were exceeding a reasonable safe speed (12.8%) than were exceeding the posted speed limit (.9%)."

Another safety concern is drivers who speed in lower speed limit zones in order to make up for lost lime.  A fleet of 103 safety managers responded to a survey about speed limiters and 88% said that truckers drive faster in speed zones below the speed limiter set speed to make up time.

In addition to the safety concerns that speed limiters will impose, there is also profit loss to consider for the small owner-operators.  Driving 65 mph instead of the maximum 70 mph or above that is allowed in 26 states would cost drivers 50-55 miles a day.  This translates to a loss of up to $85.25 per day or $22,165 a year.

In a recent survey conducted by the OOIDA Foundation, 82% of the drivers said they would rather work for a company that does not have speed limiters.  Many of the Association's members had concerns about lack of passing speed, increased congestion, and being rear-ended.  The vast majority said that uniform speed limits were the best way to regulate speeding of large trucks.  Vehicles traveling at different speeds are dangerous, and increase the risk of a crash. 

Instead of a speed limiter mandate to prevent speeding, carriers could modify the fundamental and structural problems that create incentives for speeding, such as compensation of drivers by mile and lack of pay for substantial amounts of time spent waiting to load and unload.  Speeding is often a function of the economics of trucking.  The perceived need to speed will be eliminated if carriers pay per hour, pay bonuses, or increase per mile pay for compliant driving.

OOIDA obviously does not condone speeding or other unsafe driving habits. In fact, OOIDA has urged truckers to comply with all state laws and federal regulations.  Instead of putting speed limiters in trucks, OOIDA wants to put safe drivers in trucks.

OOIDA has strongly advocated for a mandatory comprehensive entry-level driver-training curriculum, and endorsed the implementation of a graduated CDL system, apprenticeship program, and/or other forms of improved driver training.  This would improve the quality of commercial truck drivers and keep unsafe and unprepared drivers off the road.