Due to concerns about the uncompensated damage trucks cause to our highways, Congress maintains reasonable limits on the size of trucks on the Interstate Highway System — at 80,000 pounds in weight and no more than two, 28-foot trailers for total length.

In 2016, the U.S. Department of Transportation (DOT) released the final results of a comprehensive study examining the impact of increasing current federal truck size and weight limits and further concluded that no changes to federal policy on truck size and weights should be made. These limits make good sense. The fuel taxes and other highway-related fees that commercial trucks pay fall far short of covering the costs of the highway damage they cause. In contrast to trucks, freight railroads offer a sustainable and efficient way to move cargo across the country while operating on privately owned infrastructure they have invested billions into maintaining and upgrading.

Now proponents are pursuing avenues at the state and federal level to increase federal limits on truck weights from 80,000 pounds to at least 91,000 pounds — a jump of almost 14% in truck weight — while also pushing Congress to force states to allow double-trailer Twin 33 trucks. Both would lead to more truck freight, which would further stress the nation’s deteriorating roads and bridges. At a time when policymakers continue to call for investment into and improvement of the nation’s infrastructure, knowingly taking steps to further damage the nation’s federal highway system is misguided policy.

In fact, a recent study using decades of actual truck and rail pricing and demand data — including 2019 data — found that relaxing weight and size limits would “lead to unaffordable wear and tear on highways and the diversion of freight traffic from congestion-reducing, environmentally friendlier non-highway alternatives to all-highway truck routings.” The study also highlights that the diversion volumes vary significantly by truck configuration. An increase in allowed total gross truck weights from 80,000 to 91,000 pounds (but with no change in trailer length) is estimated to result in the diversion of 2.6 million annual railroad carloads and 1.8 million intermodal units. Alternatively, an increase of truck weights to 120,000 pounds combined with twin 33-foot trailers leads to a predicted diversion of 7.5 million annual rail carloads and 8.5 million diverted intermodal shipments.

Freight Rail Policy Stance: Congress should not increase truck size or weight limits. Any increase in truck size or weight limits, including 91,000 pound trucks or “Twin 33” foot double-trailers, would force more costs onto taxpayers because larger trucks would result in greater damage to infrastructure.

Download Fact Sheet