The National Highway Traffic Safety Administration is moving ahead on a rulemaking on speed limiters for heavy trucks, which had its start four years ago with petitions by two trucking interest groups.

In separate petitions in 2006, the American Trucking Associations and Road Safe America asked NHTSA to consider requiring limiters set at 68 mph in heavy trucks. The two groups differed on timing, ATA requesting limiters in all new trucks, and RSA in all trucks built after 1990. ATA later modified its request to all trucks built after 1992 - which means virtually all highway trucks.

NHTSA has been gathering information and comments for several years and last week said it will publish a Notice of Proposed Rulemaking in 2012. That process will not necessarily produce a rule, but the announcement does signal the agency's strong interest in limiters.

The agency said it has received about 3,850 comments on the issue, many from private citizens who support limiters. 

Fleet Support for Speed Limiters

Among the carriers that commented were Schneider National and J.B. Hunt Transport, both of which already limit their trucks and support a mandate. 

Schneider reported that before it installed speed limiters in 1996, trucks without limiters accounted for 40 percent of the company's serious collisions while driving 17 percent of its total miles, the agency said in its commentary last week.

Hunt said limiters will create a speed differential on the highway, but that the risk from that differential is outweighed by the risk of speeding, the agency said.

Schneider and Hunt are among nine carriers that joined the public interest group Road Safe America in its petition. The other carriers are C.R. England, H.O. Wolding, ATS Intermodal, Dart Transit Co., U.S. Xpress, Covenant Transport, and Jet Express.

Safety and Perception

The safety advocacy community supports limiters. The Insurance Institute for Highway Safety says, for instance, that limiters will create economic as well as safety benefits. 

The Technology and Maintenance Council of ATA underscored the economic benefits by noting that an increase of 1 mph results in a 0.1 mpg increase in fuel consumption, and that for every 1 mph increase over 55 mph there is a 1 percent reduction in tire tread life.

ATA undertook the initiative in part for safety, but also because speeding may contribute to a poor public perception of the industry. The association said in its analysis that faster vehicles have less time to respond and stop in emergencies, and that high speed increases the severity of accidents.

ATA also found that research on the impact of a speed differential between cars and trucks is not conclusive, although the risk of an accident is lowest near the average speed of traffic and increases for vehicles going a lot faster or slower than that average.

Opposition to Speed Limiter Mandate

The speed differential was cited as cause for opposition to limiters by ATA's affiliated conference, the Truckload Carriers Association, as well as the Owner-Operator Independent Drivers Association and individual owner-operators, the agency said.

OOIDA also contends that ATA wants to force limiters onto all trucks so its members can compete for drivers with carriers that have not limited their trucks, the agency said. 

The agency noted that the Truck Manufacturers Association provided an estimated one-time cost of $35 to $50 million to develop electronic control modules with tamper-resistant limiters. Tamper-proof limiters would be more expensive: $150 to $200 million. The distinction will need to be resolved, if the agency decides to proceed with a rule: ATA in its petition asked that the ECM be made tamper-resistant rather than tamper-proof. 

Research that the agency reviewed shows that there is a potential for limiters to reduce crash severity. 

The agency also learned in its review that the U.S. is a latecomer to speed-limiting on trucks: the European Union has limited trucks and buses to 62 mph since 1994, and Australia has limited trucks to 62 mph since 1990. Japan limited its trucks to 56 mph in 2003, and Quebec and Ontario limited trucks to 65 in 2009. All of these places safety and economic benefits from the regulations, and the Canadians added environmental benefits to that list.