Auto makers must phase in improved side-impact crash protection that meets federal standards beginning in 2009, the government says in a newly adopted rule.

The new standard, says U.S. Transportation Secretary Mary E. Peters, will require auto makers for the first time to provide head protection in side-impact crashes, as well as enhance other protections for passengers in such crashes.

The National Highway Traffic Safety Admin. will begin using a dummy representing a small adult female in side-impact performance testing, and plans to also add a new and more technically advance dummy representing a male of average height.

NHTSA does not require specific technologies to met the new standard, but instead says it expects auto makers to meet the requirement with various types of innovative head, chest and pelvis protection systems, such as side curtain air bags and thorax air bags.

NHTSA estimates that the new standard could save 300 lives and prevent 400 serious injuries annually. Side impact crashes account for 28% of all fatalities the agency says.