Are Speed Limiters in Every Trucker's Near Future?

Limiting trucks to a predetermined set speed limit has long been a controversial topic, especially among truck drivers. And while many of the nation's largest carriers already have speed limiters installed on all their rigs, many drivers still refuse to work for fleets that limit the speed on their vehicles. There has been much talk over the years about federally mandating speed limiters on trucks primarily for safety reasons.

The safety benefits of speed limiters, while highly debated by opponents, are proven, according to the Federal Motor Carrier Safety Administration (FMCSA). Trucks equipped with speed governors have a 50% lower crash rate than trucks not equipped with speed control devices, according to the results of the second phase of a study by FMCSA on the impact of the use of speed limiting devices in commercial vehicles. "Results from multiple analyses indicated a profound safety benefit for trucks equipped with an active speed limiter," the FMCSA report states. The study represents the most comprehensive investigation that has ever been conducted on speed limiters (SL), according to FMCSA. The study included data from 20 truck fleets, approximately 138,000 trucks and analyzed more than 15,000 crashes. The findings showed "strong positive benefits for speed governors." Results indicated that trucks equipped with speed limiters had a "significantly lower SL-relevant crash rate (approximately 50%) compared to trucks without SLs," the study found. Exceeding the speed limit or driving too fast for conditions was a contributing factor in 8% of all reported large truck crashes in 2009, according to the National Highway Traffic Safety Administration. According to the FMCSA Large Truck Crash Causation study 22.9% of all large truck crashes and 10.4% of large truck/passenger car crashes were coded as "traveling too fast for conditions." The study also concludes that the cost of speed limiter technology is negligible as it is a standard feature on new trucks (owners only need to activate and set the SL). "SLs are standard equipment on new trucks and have been used for some time, with the core technology built into the Engine Control Module (ECM). Historical problems related to driver tampering have been alleviated by the current electronic systems. Because the SL capability is standard, the cost to implement SLs is negligible, although some additional costs do accrue for fleets that use external maintenance centers to change SL settings," the report states. Opponents of speed governors argue that safety can be compromised since speed-limited vehicles cannot accelerate to avoid traffic conflicts (for instance, in merging situations), and the slower speed of these vehicles relative to the surrounding traffic creates speed differentials. Studies have shown there can be an increased risk of crashes when speeds of vehicles traveling on the same highway are different. "Domain research on the potential downside of speed deviations among vehicles that could occur due to the interaction of SL-equipped vehicles and those without SLs seems to be far outweighed by the significant safety benefits associated with a reduction in absolute speed afforded by SLs," the FMCSA study concludes. "The positive findings in this study were consistent with the bulk of the literature on this topic indicating significant safety benefits associated with speed reduction which can be achieved through the implementation of SLs." A series of groups including the American Trucking Assns., the automobile group AAA, the Insurance Institute for Highway Safety and Advocates for Highway and Auto Safety all support speed limiters. However, the Owner-Operator Independent Drivers Assn. has long opposed mandating speed limiters. "OOIDA is opposed to a mandate for speed limiters because the mandated use of them would decrease safety, since the interaction between large trucks and automobiles would increase. First, there is no clear evidence that supports 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," according to the OOIDA Foundation. OOIDA claims studies show that a higher variance of vehicle speeds in traffic flow increase the risk of an accident, and speed limiters cause speed variance. "Regardless of the average speed on the highway, the greater the driver's deviate from the average speed, the greater his chance of being involved in an accident. Low speed drivers are more likely to be involved in accidents than high-speed drivers are," the independent driver group says. 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, OOIDA says.

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. Speed is a factor in some crashes but it's mixed in terms of the relationships of speed to the speed limits. Data shows crashes that occur when the vehicle was traveling above the speed limit are minor compared to the case of traveling too fast for conditions, OOIDA asserts. "As cited in Office of Motor Carrier Safety 1999, up to 21% 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 a much higher percentage of drivers involved in crashes that were exceeding a reasonable safe speed (12.8%) than were exceeding the posted speed limit (.9%)." OOIDA says 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, OOIDA notes. In a recent survey posted by OOIDA, 82% of the drivers said they would rather work for a company that does not have speed limiters. "Many of our drivers had concerns about lack of passing speed, increased congestion, and being rear-ended," OOIDA explains. "The vast majority said 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." In the end, however, it may not be safety or federal intervention that results in all big rigs being limited to a set speed. What most truckers don't know is that in the near future truck builders may be forced to set top speeds on their over-the-road rigs to comply with newly mandated federal fuel economy standards on big trucks. In order to meet the first round of fuel mileage standards, many over-the-road tractors will most likely require speed limiters to set maximum speed of the truck. Dave McKenna, director powertrain sales and marketing for Mack told Fleet Owner magazine that over-the-road trucks will be most impacted by the fuel economy regulations where he predicts road speed limiters will soon become standard. The reason speed limiters will help OEMs reach fuel economy standards is undeniable. According to Bridgestone, research shows that speed is the largest single factor affecting fuel economy. In tests, vehicles went from about 5.1 miles per gallon at 75 mph to about 7.1 miles per gallon at 55 mph. A change from 75 mph to 65 mph is almost practical. At 75 mph, test vehicles achieved about 5.1 mpg. At 65, the figure was 6.0 mpg. That's about an 18% improvement in miles per gallon, for a cost of about 15.5 percent in extra travel time. The amount of fuel saved is about 15%. Bridgestone tests indicate for every 1 mph you increase speed (between 55 mph and 75 mph), you cut your miles per gallon by about 1.6%. U.S. Xpress, one of the nation's most savvy truck fleets, uses speed limiters universally in its fleet and has seen a "definite benefit" in fuel savings. But getting drivers on-board can be the trickiest part of the fuel economy equation, Chairman Max Fuller says. "Anytime you cut the drivers' ability to make money there is going to be heartburn with it. You can't blame 'em. You have to give them something in return. We offered the drivers more in pay, but we make up for it in fuel savings." Communication with drivers is key. "The driver community is really sharp," Fuller says. "They understand what 200 gallons of fuel costs, so they've been generally accepting. If you don't communicate and when you make a policy change you're going to get backlash. When you give drivers the facts especially when fuel prices are high they are usually ready to work with you, especially if you address their issues as well." Mack's McKenna says that while speed limiters on all trucks in the U.S. is a foregone conclusion, he hopes that the U.S. doesn't don't go the way of Canada and set the limit at the exact same speed for all trucks on the highway. "In Canada, they set speed limiters on all heavy duty trucks at the same speed, with unintended consequences," McKenna says. "With all the trucks geared to run at same speed, they can't get out of each other's way. It creates huge traffic jams because the trucks can't pass each other."