WASHINGTON - The U.S. government plans to require automakers to meet more rigorous crash test standards for side-impact accidents, Reuters reported Wednesday. The National Highway Traffic Safety Administration new proposed standards would effectively hold automakers to their pledge to equip all new vehicles with advanced airbag systems that protect the head by 2009. The government estimates that it will cost the auto industry an extra $1 billion to meet the new crash test standards. Regulators hope to make the rule final as early as next year but most safety and industry experts agree it could take longer, the news service reported. Currently more than half of 2004 models offer side airbags with head protection as standard or optional equipment. This includes the most advanced system called side curtains, which drop from the ceiling to cover windows. But insurance industry experts say rising consumer demand for safer cars is now pushing auto manufacturers to accelerate the pace in offering better side airbags as standard equipment. Just under 10,000 people were killed in side-impact crashes in 2002, the latest available statistics.