A person was ejected from a vehicle in this Gaithersburg crash. (Courtesy of Montgomery County Fire)

There are about 1.7 million rear-end collisions on U.S. roadways each year. About 1,7000 people die in those collisions and another 500,000 are hurt.

Many of those most-common-of-all car accidents could be avoided if auto makers begin making collision avoidance systems standard equipment in their vehicles, the National Transportation Safety Board said in a recommendation issued Monday.

“You don’t pay extra for your seat belt,” said NTSB Chairman Christopher A. Hart. “And you shouldn’t have to pay extra for technology that can help prevent a collision altogether.”

The NTSB estimated that 80 percent of the deaths and injuries resulting from rear-end collisions could be prevented by collision avoidance systems, which are available in some cars but not required on all of them.

“Research shows that front-crash prevention systems, particularly those that can brake automatically, are significantly reducing front-into-rear crashes,” said Russ Rader of the Insurance Institute for Highway Safety.

The Governors Highway Safety Association also endorsed the NTSB action.

“We strongly support the recommendation,” said Jonathan Adkins, the GHSA’s executive director. “The key to achieving the next wave of success in reducing highway deaths is technological advances.”

In a report accompanying the recommendation, the NTSB pointed to a study by the National Highway Traffic Safety Administration which found that 87 percent of rear-end collisions happened because the driver simply wasn’t paying attention to the road.

The NTSB said that cell phones and other non-driving related systems in cars contributed to that distraction.