Increasing truck size and weight could be a boon to efficiency and safety.

The National Private Truck Council has joined the Steering Committee of the Coalition for Transportation Productivity (CTP), a group of shippers, motor carriers and their associations seeking to increase truck weight limits.

CTP is asking Congress to allow states to increase the federal vehicle weight limit to 97,000 lbs. for vehicles equipped with an additional (sixth) axle for travel on Interstate highways.  These vehicles would have to meet the same safety standards as trucks currently allowed on Interstates.  The coalition also supports a user fee on units equipped with the additional axle; the funds generated from the fee would be dedicated to bridge repair.

Six-axle trucks carrying 97,000 lbs. get 17% more ton-miles per gallon of fuel than five-axle trucks carrying 80,000 lbs.  The U.S. Dept. of Transportation estimates that use of six-axle trucks would save 2 billion gals. of diesel fuel annually and reduce engine emissions by 19% per ton-mile.

“This is not a new idea,” says  Rick Schweitzer, NPTC general counsel, who represents the council on the CTP Steering Committee.  “In 2000, DOT conducted a study and concluded that increased truck weights would not only reduce costs, but the additional axle would actually save $2.4 billion in pavement restoration over 20 years,” he continued.  “As far back as 1990, the Transportation Research Board looked at this issue and found that the increased weights would result in a 1.6% reduction in the cost of goods movement by truck and that pavement costs would not be significantly affected.”

Moreover, safety is not adversely affected by the additional weight.  In the U.K., which adopted a 97,000-lb. limit with six axles in 2001, the number of heavy-truck-related fatalities fell by 35% as of 2006.  More recently, under a pilot program now made permanent, the state of Maine has allowed six-axle, 97,000-lb. trucks on its Interstates since 2010.  In 2014, fatalities on Maine roads were the lowest in 70 years, and the Maine Bureau of Highway Safety specifically noted that congressional action allowing Maine to permit heavier, six-axle trucks full access to the Interstate highways may have “helped to make roads safer.”

In addition, NPTC supports increasing the federal length limits on double trailers from 28 to 33 ft.  This additional capacity would improve the productivity of those private carriers that transport lighter and less dense freight.

In MAP-21, Congress required DOT to conduct a new Comprehensive Truck Size and Weight Limits Study addressing differences in safety risks, infrastructure impacts, and the effect on levels of enforcement between trucks operating at or within federal truck size and weight limits and trucks legally operating in excess of federal limits.

The study was supposed to be submitted to Congress by November 2014, but it has not yet been published.  Our concern is that the department will not release its conclusions in time for Congress to consider them as part of the highway reauthorization bill under consideration this year.  We need DOT to finish its study, and for Congress to upgrade our truck size and weight rules to permit improved productivity, lower emissions, reduced highway congestion, and fewer accidents.