Twin 33-Foot Trailers Would Boost Safety, Efficiency, New Analysis Concludes

John Sommers II for TT

A new analysis by traffic safety researcher Ronald Knipling has concluded that widespread adoption of twin 33-foot trailers would boost safety and efficiency for U.S. drivers, consumers and businesses.

“Allowing widespread use of twin 33 trailers is commonsense policy,” Knipling said in a March 13 statement. “Not only are they more stable at highway speeds, the efficiency gains mean we have fewer trucks on the road.”

“Fewer trucks means fewer accidents, less wear and tear on our roads and more focused enforcement by weigh stations for all types of trucks. It’s a win-win for drivers, consumers, businesses and the economy.”

The analysis, entitled “Twin 33 Foot Truck Trailers: Making U.S. Freight Transport Safer And More Efficient,” was commissioned by Americans for Modern Transportation, a  coalition of shippers and retailers led by UPS Inc., FedEx Corp. and supporting the nationwide access of twin 33-foot trailers.

Knipling’s study concluded that a shift to twin 33s would result in reduced exposure to risk, fewer annual truck accidents, improved fuel efficiency, lowered emissions and reduced traffic.

The study’s key findings include:

• Widespread adoption of twin 33s would have reduced truck miles driven by 3.1 billion in 2014, avoiding 4,500 accidents annually.

• In 2014, the shift to twin 33s would have saved 255.2 million gallons of fuel and reduced carbon emissions by nearly 3 million tons, and clean-air improvements would be like taking 551,000 cars off the highways.

• A shift to twin 33s would have dramatically reduced congestion, decreasing travel delay time by 53.2 million hours.

• Overall, a shift to twin 33s would save $2.6 billion in transportation costs.

“While the trucking industry continues to innovate, it’s been more than 25 years since we upgraded our transportation policies,” group spokeswoman Melissa Manson said. “Business and consumer trends demand a modern transportation system.”

The prospect of allowing twin 33 trailers on all U.S. interstates has been controversial for several years.

Two years ago, Congress sought to adopt a proposal that would have approved twin 33s industrywide. But pushback from key senators resulted in the proposal’s removal from a fiscal 2016 spending bill.

Opponents have said that twin 33-foot trailers may endanger motorists unfamiliar with longer trailers on roadways.

In June 2015, Transportation Under Secretary Peter Rogoff told congressional leaders that data collected for a congressionally mandated truck size and weight study that included twin 33s were so limited that the Department of Transportation could not recommend changes to current federal policy.

Rogoff said in a letter that the $2.3 million technical research report “revealed very significant data limitations that severely hampered FHWA's efforts to conclusively study the effects of the size and weight of various truck configurations.”

“At this time, the department believes that the current data limitations are so profound that the results cannot accurately be extrapolated to predict national impacts,” Rogoff wrote. “As such, the department believes that no changes in the relevant truck size and weight laws and regulations should be considered until these data limitations are overcome.”

UPS ranks No. 1 and FedEx is No. 2 on the Transport Topics Top 100 list of the largest U.S. and Canadian for-hire carriers.