Truck Size and Weight

Our Ask:

  • Oppose any provisions that would increase maximum truck size or weight (TSW) limits on federal highways.

Environmental Consequences

Rail is the safest and most environmentally friendly way to move freight over land. U.S. freight railroads, on average, move one ton of freight more than 470 miles per gallon of fuel. Moving freight by truck increases greenhouse gas emissions by up to 75%, on average. U.S. Environmental Protection Agency data show freight railroads account for only 0.6% of total U.S. greenhouse gas emissions and only 2.0% of transportation-related sources (trucking, shipping, air, etc.).

Current efficiency with 28-foot trailers: vs. Diminished efficiency with twin 33s:
28-foot trucks   twin 33s

Photos courtesy of the Coalition Against Bigger Trucks (CABT)

Negative Infrastructure Impact

In 2016, the U.S. Department of Transportation (DOT) recommended to Congress that no changes be made to TSW limits, concluding that heavier and longer trucks would cause billions of dollars in infrastructure damage to roads and bridges that are primarily paid for by the public through taxes.

Threat to Public Safety

Allowing bigger and heavier trucks on the federal or state roadways will increase road congestion and crash risk. Congress last increased the federal weight limit in 1982. Those pushing for longer and heavier trucks said it would result in fewer trucks on the road, but in fact, the number of trucks registered in the U.S. and the mileage of trucks traveled has increased by 91%.

Recent DOT data has shown that fatalities in crashes involving at least one large truck (gross vehicle weight rating of more than 10,000 lbs.) as a percentage of total fatalities increased from January through March 2022. Total estimated fatalities in crashes involving at least one large truck increased by 10 percent in year-over-year data through June 2022.

Increasing limits would only make supply chain issues and congestion worse. Some types of configurations of bigger trucks – or what are known as “twin 33s” – exacerbate supply chain bottlenecks, introducing greater inefficiencies to intermodal freight traffic, as railcars would be able to carry fewer overall trailers. That means longer wait times for goods carried by rail.

Heavier weights increase damage to roadways, and increase the risk to the public.

Truck Configuration Impact Studies

Analysis of the impact to the transportation network of changing truck size or weight, commonly referred to as “truck diversion” studies, have shown that 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 to the roadways. 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 – increasing congestion, road damage.

  • June, 2020 - ATI Diversion Study
    • Short lines will need to make artificial and inefficient economic and management decisions. They’ll be forced to put their limited resources toward increasing operating staff on the train — when they’re already struggling to hire enough of those qualified individuals — instead of putting that capital where it may be better used, like making improvements to track and structures that are critical for the efficient movement of goods and freight.
    • It risks the short line industry’s ability to service their customers and provide an economic engine to the communities in which they operate, and the modal shifts that it would inadvertently cause would not serve the American public well.
  • July, 2021 - Colorado Barley Diversion Study
  • July, 2021 - Ohio Steel Coils Diversion Study
  • September, 2007 - MIT Diversion Study

Key Takeaway:

ASLRRA urges policymakers to oppose any action increasing TSW, averting a safety risk to the motoring public, negative environmental impact, and damage to over-burdened highway infrastructure.