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DOT: We still can't tell you what to do, but don't change anything

DOT: We still can't tell you what to do, but don't change anything

Final report to Congress calls for no change to federal truck weight, trailer length restrictions

A good deal of information regarding longer or heavier truck configurations is lacking, and what is available now doesn't support any particular federal policy adjustments. That's what the U.S. Dept. of Transportation (DOT) claims in its final report to Congress on truck size and weight limits, but DOT again takes the further step of recommending that no changes be made.

"The Department stresses that no changes in the relevant Federal truck size and weight laws and regulations should be made until these [data and information] limitations are overcome," DOT states in the report, which was issued April 14.

DOT's position remains unchanged from a preliminary release last June. The report came as a result of provisions of the Moving Ahead for Progress in the 21st Century Act — MAP-21 — that called for study of existing federal truck size and weight limits back in 2012. With some exceptions, those limits allow for trucks with a single 53-ft. or twin 28 or 28.5-ft. trailers and up to 80,000 lbs. max gross vehicle weight, or GVW.

The underlying questions here are whether to allow higher GVWs, possibly for tractor-trailers with more axles — call that the "heavier argument" — or allow longer trailer combos like twin 33-footers, also known as "pups," which can be thought of as the "longer argument." It's an important distinction, because there are groups supporting and opposing the two potential changes separately as well as both of them together.

And make no mistake, these arguments are not new. Truck weight and length have been discussed and debated at the federal level for decades, and the heavier/longer proposals have changed very little over that time. The present federal length and weight limits for commercial trucks date back to the Surface Transportation Assistance Act of 1982.

Nor is much of this DOT final report to Congress, which concludes some four years of study, new. The agency included a series of accompanying technical reports with the June 2015 preliminary release, at that point calling for public comment and further review. Notably, the National Academies of Sciences released an evaluation of those reports in Oct. 2015 and found they came up short.

"At the least, the report could have provided a framework for understanding all the costs and benefits" related to allowing heavier trucks and/or longer trailer configurations, the National Academies' Transportation Research Board wrote. Like DOT, the board noted the lack of information: "The most critical needs are for better understanding of how truck traffic affects crash risks and how it affects bridge-related costs."

One of the key problems in that regard is that in most cases, states aren't recording specific information about longer trailers or heavier weight in heavy truck crashes. So one of the central arguments in this issue — whether heavier trucks or longer tandem trailers are safer or not, how often they're involved in crashes, etc. — can't be answered with much of any hard data.


The American Trucking Assns. and a number of less-than-truckload (LTL) carriers have supported allowing twin 33-ft. trailers without raising the 80,000-lb. max gross vehicle weight. The argument is that these carriers often fill available trailer space well before they reach that maximum weight, so the longer twin trailers would allow them to carry more and ultimately run fewer trucks on the road. Since the trucks would still have the same weight limit, they wouldn't be any heavier than currently allowed, and thus stopping performance of the trucks shouldn't be affected.

The U.S. Chamber of Commerce also supports twin-33s. "The Chamber strongly supports efforts to improve productivity for the less-than-truckload industry through allowing twin 33-foot trailer combinations, which would boost American businesses burdened with higher costs resulting from inefficient volume restrictions," wrote R. Bruce Josten, the chamber's executive vice president of government affairs, in a letter to the Senate last November.

But the Truckload Carriers Association (TCA) cheered the following month when provisions that would've allowed twin-33s were cut from the Fixing America's Surface Transportation Act long-term highway funding bill. TCA contends that allowing the longer trailers would make them the new industry standard; require carriers to make significant new equipment purchases; worsen the driver shortage because drivers lack experience with tandem trailers; make already limited truck parking spaces unusable due to added length requirements; and other negative effects.

Regarding changes in weight limits, food and agricultural producers — which often transport goods in bulk and operate right at those limits — are all for it. "In the agriculture and food industries, our farms and businesses are growing and making products more resourcefully, but outdated federal transportation rules force trucks to leave the farm and our plants when they are partly empty," reads a Nov. 3 letter sent to the House of Representatives signed by 77 farm and food organizations. The groups support a new federal weight limit of 91,000 lbs. for six-axle trucks.

And for another view, groups such as the Coalition Against Bigger Trucks (CABT) lobby against allowing either longer or heavier trucks on interstate highways. CABT hits visitors to its site right away with a message that longer/heavier trucks "endanger motorists, wreck bridges and roads and cost taxpayers."

While the final DOT report to Congress cites a lack of information and data in a number of areas and ultimately doesn't support federal policy changes on truck weight and trailer length, the National Academies' Transportation Research Board (TRB) faced a similar task around the turn of the millennium. TRB, however, conducted a study and did actually make recommendations, which Congress had specifically requested under the 1998 Transportation Equity Act for the 21st Century.

Like DOT, TRB noted the lack of information on costs and benefits of truck transportation. "Every past body that has examined these issues has encountered the same difficulty," TRB's report reads. Yet TRB suggested that the data limitations don't preclude the possibility of regulatory changes.

"Opportunities exist for improving the efficiency of the highway system through reform of federal truck size and weight regulations. Such reform may entail allowing larger trucks to operate," the report states. Current regulations, according to TRB, "are poorly suited to the demands of international commerce" and force freight traffic off of federal highways and onto less-restrictive state roadways. 


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