Jan. 1 – A new truck size and weight study released Wednesday by the U.S. Department of Transportation is sure to add fuel to the controversy about longer combination vehicles.
The book-length volume, while technically a draft, outlines the effects of several different scenarios involving greater use of LCVs such as triple trailers. Truck sizes and weights have been frozen since 1990. More than a dozen states currently allow rigs longer than 65 feet and heavier than 80,000 pounds, in various configurations.

One of the conclusions in the report is that allowing LCVs coast to coast would reduce the number of tractor-trailers on the road, but would probably increase the safety risk from truck accidents – a conclusion sure to be used as ammunition by anti-truck safety groups such as Citizens for Reliable and Safe Highways. Other conclusions include higher highway and bridge costs, lower freight rates, and more freight moving to trucks rather than rail.
The study will officially be completed next spring, and will be the most extensive look at truck size and weight impacts since 1982.
American Trucking Assns. President and CEO Walter McCormick wasted no time in attacking the study as “deeply flawed and a waste of taxpayers’ money. It looked at hypothetical transportation scenarios that do not exist today and examined them under fantasy conditions. It is little wonder that the [DOT] has warned readers that the study ‘is not a policy vehicle in any sense.’”
According to ATA, the methodology of the report has also come under fire from Rep. David McIntosh, R-IN, chairman of a key House Government Reform and Oversight subcommittee. In a letter to Secretary of Transportation Rodney Slater, McIntosh reportedly expressed concern that the report would provide legislators with little, if any, policy guidance.
“This study examines changes to truck size and weight laws that have never been proposed by the trucking industry,” McCormick said. “It is an exercise in conjecture.”
According to the ATA, the study assumes extensive, nationwide, longer combination vehicle networks that are more than three times longer than the current LCV network. ATA says the networks do not appear to take into account roadway geometry, state permitting processes, traffic levels, shipper needs, or other considerations that would make these routes legitimate candidates for LCV expansion.
ATA also says the study focuses on truck configurations that do not exist and are unlikely to, such as a seven-axle triple with a GVW of 132,000 pounds.
In addition, ATA says, FHWA refused to use data from a study it commissioned for use in the size and weight study, which showed that the accident rates of LCVs are half that of common five-axle tractor-trailer units.
The study was released as lawmakers prepare to convene next week. The ATA plans to join four Western governors in lobbying Congress to let states set their own LCV rules.