The plan for rule-making to require speed limiters for heavy-duty vehicles has been postponed until May, according to the Federal Motor Carrier Safety Administration (FMCSA). Devices known as electronic speed governors or speed limiters limit the fastest speed at which a truck can go.

The trucking industry is divided on the FMCSA’s proposal to mandate speed limiters for trucks above 26,000 pounds. Supporters include safety organizations and some large carriers. Opponents include drivers and truck driver associations, especially those that represent independent drivers.

The multiple delays of this proposal reflect the fierce debate about speed limiters among the industry. Speed limiter mandate supporters contend that they improve road safety by lowering the number of accidents brought on by speeding, while their detractors, mostly truck drivers, argue that speed limiters actually harm overall safety.

Speed limiters could prevent drivers from keeping up with the flow of traffic, overtaking a dangerously slow vehicle, or avoiding other hazards on the road. While counter-intuitive for the regulators at the FMCSA, speed limiters can truly make drivers less safe. Only drivers are behind the wheel to make the decisions of when to speed beyond the limit.

In addition to safety as a primary concern, trucks would have to be fitted with limiters, which adds a new expense. Such a cost would be more easily borne by large trucking companies as opposed to their smaller competitors.