The National Transportation Safety Board on Thursday issued seven recommendations urging the National Highway Safety Administration to take action to improve the safety of tractor-trailers.

These recommendations stem from a 2013 NTSB safety study on straight-trucks and other research, which identified issues that apply to tractor-trailers as well.

Like large single-unit trucks, tractor-trailers may have blind spots that can reduce the ability of drivers to see other vehicles and road users, according to NTSB. Researchers found that limited field of view can increase the risk of death or injury among passenger vehicle occupants, pedestrians, bicyclists, and motorcyclists when drivers of tractor-trailers change lanes, make turns, go straight, or back up.

Collisions with the sides of tractor-trailers resulted in about 500 deaths each year and that many of these deaths involved side underride, according to NTSB. Researchers also found that current trailer rear underride guard standards are outdated. The recommendations call on NHTSA to require that both newly manufactured truck-tractors and trailers be equipped with side underride protection systems, and that revisions be made to improve trailer rear underride guard standards to better protect passenger vehicle occupants from fatalities and serious injuries.

Finally, the NTSB asked NHTSA to address the issue of data collection on trailers. When a tractor-trailer gets into an accident, police officers routinely record basic information about the truck-tractor component of the tractor-trailer, including the model year and vehicle identification number. However, information about the trailer component is usually missing from federal and state databases.

Having this information could help with evaluation of safety standards and determine whether certain trailer designs and equipment should be altered to reduce injury risks to passenger vehicle occupants, claims NTSB.

The board is recommending that NHTSA add information on trailer model year and trailer vehicle identification numbers to its national database of fatal crashes and encourage states to add trailer information to their crash databases.

The National Transportation Safety Board is an independent Federal agency charged by Congress with investigating every civil aviation accident the United States and significant accidents in other modes of transportation – railroad, highway, marine and pipeline. It makes recommendations to U.S. Transportation Department agencies, such as NHTSA, but cannot mandate new policies or regulations.