DOT Officials Altered Report to Remove Scientific Evidence on Safety Devices in Trucks

Published Dec 19, 2023

What happened: After an unusually in-depth stakeholder meeting with industry representatives, officials at the Department of Transportation (DOT) ordered the removal of scientific research and science-based recommendations from an agency report. The DOT report had examined the research on truck collusions and had provided recommendations on how to regulate trucks to reduce the risk of death for pedestrians and cyclists hit by trucks.

Why it matters: When agency officials overstep their boundaries and delete scientific evidence from a report, they are placing politics above science and undermining the scientific research generated by agency researchers. Without the best available science to guide DOT decisionmaking on the safety of commercial trucks, the public’s safety was endangered in the process.


In 2018, officials at the Department of Transportation (DOT) required that agency researchers remove scientific language from a report that examined how to reduce fatalities when pedestrians and cyclists are hit by commercial trucks. Specifically, the DOT report recommended that, based on the science, the DOT should issue federal regulations that required trucks to install a safety device called a side guard. Side guards are devices made of plastic, aluminum, or steel that hang between the truck’s front and rear wheels and prevent pedestrians and cyclists from tumbling beneath the vehicles and getting crushed. While they are not widely in use in the US, side guards are required to be installed on trucks in dozens of countries.

In a highly unusual process, DOT officials met repeatedly with representatives from the nation’s largest trade group for trucking companies, the American Trucking Associations, to discuss unpublished research. The industry group repeatedly pressured DOT officials to alter the scientific report. After one of those meetings, in December 2018, the DOT official who was overseeing the report process emailed the DOT researchers and wrote the following, “PLEASE delete any mention of a recommendation to develop … any regulation. An industry standard is acceptable, but no mention of ‘regulation.’” The DOT supervisor who oversaw the project, Quon Kwan, stated the department’s deference to the trucking industry ultimately contributed to his retirement in 2019.

Similar concerns have been raised about a different, heavier side guard that is designed to prevent cars and other passenger vehicles from getting wedged beneath large commercial trucks during roadway collisions. For decades, federal regulators have ignored credible scientific research to install these heavier side guards and the trucking industry has repeatedly lobbied the federal government against regulating the installation of these safety devices.

Additionally, a career official from the National Highway Traffic Safety Administration (NHTSA), removed key language on side guards from the DOT report. Based on an industry analysis, the NHTSA official argued that side guards would cost too much and would not save many lives. DOT researchers responded by carrying out their own analysis and found that side guards had the potential to save the lives of up to 52 people every year, far more than the industry analysis had concluded.

Due to interference of DOT and NHTSA officials, the final version of the DOT report was about half the length of the original document produced by the agency researchers and contained no recommendations at all. As a result of this interference, the best available scientific evidence was not able to be released in the DOT report and therefore could not be used to save people’s lives.