The Potential Efficiency Gains of Twin 33s Climb as Volume of Goods Moved by LTL Carriers Increases

The transport of goods by truck grew across the country from 2014 to 2018. This trend was especially true for the Less Than Truckload (LTL) carriers that are relied upon to carry small freight shipments, including much of the e-commerce purchases made by consumers.

According to Alan Karickhoff, the Economic Analyst for American Trucking Associations, overall tonnage for LTL carriers between 2014 and 2018 increased by 7.6%. This growth supports the Department of Transportation’s forecast of a 45% increase in freight volumes by 2045.

If this trend continues and tonnage increases, AMT’s proposal to modernize regulations and allow a modest five-foot length increase to twin 28’ trailers becomes even more important to adding capacity to accommodate growing e-commerce volumes, increasing roadway safety, making environmental improvements and reducing wear and tear on our national infrastructure.

As Ronald R. Knipling, Ph.D., stated in his research “Twin 33 Foot Truck Trailers: Making U.S. Freight Transport Safer And More Efficient,” trucks often “cube out” before they weigh out. 

Calculations from Knipling’s original research used 2014 tonnage data to measure the benefits that could be realized if AMT’s proposal to allow twin 33’s was in place across the country. Based on the assumption that annual tonnage drives other key metrics of truck activity, the following efficiency gains would have been realized in 2018 had Twin 33’s been allowed nationwide:

  • 3.36 Billion Fewer Vehicle Miles Traveled
  • $2.8 Billion Saved in Shipping Cost
  • 57.2 Million Hours Saved Due to Less Congestion
  • 274 Million Fewer Gallons of Fuel
  • 3.12 Million Fewer Tons of CO2 Emissions

Time for action is now. AMT’s proposal comes at no cost to taxpayers, will increase safety, maximize efficiency and reduce carbon emissions. Private investment and modernization of our truck standards will drive immediate and future benefits for our nation’s transportation system. Twin 33s are already approved to operate in 20 states, and we know that this transportation solution would benefit consumers, businesses and so many others across our country.

For more information about Americans for Modern Transportation, please visit and follow @amtcoalition on Twitter.