Four highway safety groups are asking the U.S. government to require tractor-trailers and big buses to have devices that alert drivers to stopped traffic and brake the trucks if they don't respond.
The groups petitioned the National Highway Traffic Safety Administration Thursday seeking the requirement. They say the systems could prevent more than 2,500 crashes per year, but the agency hasn't required them.
The groups say that from 2003 to 2008 there were 32,000 crashes in which trucks rear-ended other vehicles, killing at least 300 people per year and injuring more than 15,000. They say only 3 percent of the 3 million tractor-trailers on the road now have the technology.
Representatives from the safety agency and trucking industry groups weren't immediately available to comment Thursday.