On Thursday,  the National Highway Traffic Safety Administration (NHTSA) issued a final rule aimed at decreasing occupant ejections in passenger vehicles. The standard, which will help reduce the number of people partially or completely ejected through side windows during rollover crashes, will begin phasing in during 2013.

"Safety is our highest priority," said U.S. Department of Transportation Secretary Ray LaHood. "This new standard will help save lives and reduce injuries by requiring vehicles to have a safety system that keeps occupants in the vehicle in a rollover crash."

Under the new rule, vehicle manufacturers must develop a countermeasure for light passenger vehicles under 10,000 lbs. that prevents the equivalent of an unbelted adult from moving more than four inches past the side window opening in the event of a crash.

The new standard will begin phasing in during 2013. All newly manufactured vehicles will be required to provide this protection by model year 2018.

"Rollover crashes are the deadliest of all crash types and this is another important step in our efforts to reduce fatalities and serious injuries that result from them," said Administrator David Strickland, NHTSA. "When fully implemented, we believe this standard will prevent on average 373 fatalities and 476 serious injuries every year."

Thursday's announcement is part of NHTSA's initiative to improve the overall safety for occupants in the event of a rollover crash. Previously, the agency issued rules requiring that all new vehicles come equipped with electronic stability control to keep vehicles from losing control and also upgraded its roof crush standard to keep the occupant compartment intact. To view the new standard click here.