April 16, 2018 12:30 PM, EDT

Panel Issues Interim Report to Accelerate Recommendations for Truck Size, Weight Limits

A specially appointed committee of academic and policy experts has issued an interim report on its plans to plug data and research gaps that have for several years delayed federal policy recommendations for changes to truck size and weight limits.

The National Academies of Sciences, Engineering and Medicine study committee said it plans to “reduce uncertainties in estimates of the impacts of changes in truck size and weight limits.”

“The plan is to specify research projects, estimated costs and timelines for research in the areas of safety, enforcement, mode shift, bridges and pavements,” said the committee’s interim report, made public April 16. The committee plans to issue a final report outlining its “research road map” in the fall.

Size and Weight Report by Transport Topics on Scribd

The committee, which began its work last summer, was appointed after a congressionally mandated U.S. Department of Transportation $2.3 million study failed to provide the needed research and data support to recommend increasing truck size and weight.



When the study was first released in June 2015, then DOT Undersecretary Peter Rogoff sent a letter to congressional leaders indicating that the research “revealed very significant data limitations that severely hampered the Federal Highway Administration’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 said in his letter.

The final version of DOT’s Comprehensive Truck Size and Weight Limits Study, delivered to Congress in April 2016, repeated Rogoff’s conclusion and recommended continuing the research. Subsequently, the Federal Highway Administration’s Office of Freight Management and Operations asked the Transportation Research Board to develop a plan for a more rigorous research program.

The National Academies study committee’s interim report:

• Summarizes research recommendations of past truck size and weight limit studies.

• Presents lists of candidate research problem statement topics on each of the five impact categories and on methods to evaluate alternative truck size and weight regulatory structures.

• Identifies criteria that the committee will take into account when deciding the priority of topics for inclusion in its research plan.

Committee Chairman James Winebrake, dean of the College of Liberal Arts at the Rochester Institute of Technology, said the committee plans to narrow down its nearly 50 specific “research problem statement topics” in the five impact areas that include pavement, safety, enforcement, mode shift and bridges.



“Not all of those topics will make it to the next round, where we start to sketch out a research program outline for each area,” Winebrake told Transport Topics. “The final report could include recommendations that the DOT collect additional data, conduct demonstration programs, establish new survey instruments or change some of its processes in order to collect better data.”

The National Academies study committee said that general-purpose information systems and databases have been the primary information resource of past U.S. truck size and weight studies.

They have included state highway agencies’ traffic, crash, and vehicle weight databases and asset management systems, as well as national research and monitoring data systems such as the NHTSA crash databases, the committee said.

“Improvements in these information systems could improve understanding of costs and benefits of changes in truck size and weight limits,” the interim report said. “Other countries have used trials and pilot studies as techniques to further improve confidence in understanding the impacts of new vehicle types.”

A research plan for evaluating changes in truck size and weight limits by means of pilot studies or trials would differ from a plan aimed solely at refining the traditional “pencil and paper” prospective evaluation method of past U.S. truck size and weight studies, the committee said.