Updated

Congress takes its closest look at auto safety on Wednesday since the Firestone tire debacle nearly two years ago, probing the safety of sport utility vehicles.

Regulators, auto makers and consumer groups were scheduled to testify at a Senate Commerce Committee hearing on rollover risks, seat belt use and other safety concerns associated with one of the most popular vehicles ever.

The spotlight will be on the nation's top auto safety regulator, Jeffrey Runge, who last month stunned the industry by criticizing SUV safety. The administrator of the National Highway Traffic Safety Administration called for meaningful and swift changes.

Runge, an emergency room physician who will be the featured witness at the hearing, is most concerned about rollover deaths and injuries in sport utility vehicles, seat belt use, and the threat posed to smaller cars by bigger and stronger SUVs.

"SUVs inflict more harm on occupants than other cars do," said Brian O'Neill, president of an insurance industry group that will release new statistics on SUV safety at the hearing.

The group's report, an analysis of government safety data, will show that sport utility fatality rates have fallen sharply in recent years and are now almost even with passenger cars. There are 22 million SUVs on U.S. roads, about 10 percent of the total number of vehicles.

But O'Neill said the analysis will also show that because of their size and weight, sport utility vehicles can cause considerable damage to smaller passenger cars in side-impact crashes.

The auto industry aggressively defended SUV safety at a news conference on Tuesday, and plans to do the same before Senate lawmakers.

"SUVs are very safe vehicles," said Sue Cischke, vice president of safety at Ford Motor Co. She said sport utility vehicles are under attack for some of their most noteworthy attributes.

"They do well in front crashes, side crashes and rear crashes," Cischke said. "Unfortunately, many people who are killed (especially in rollovers) many times are not wearing safety belts."

Acknowledging Concerns

But the industry has recently acknowledged SUV safety concerns that critics have complained about for years, and federal regulators and Congress have sharpened their focus on them.

The industry's chief lobbying group, the Alliance of Automobile Manufacturers, has released data that auto companies agree with government figures showing the fatality rate in rollovers is three times greater for those in SUVs than for those in cars.

Auto makers have also promised to work together to reduce fatalities and injuries resulting from weight and size differences of SUVs and passenger cars. Some longer term improvements could involve design changes in one or both classes of vehicles.

The car companies are trying to head off regulation, which Runge threatened to pursue if the industry did not act voluntarily.

But some critics complain the industry is ceding a little ground now to ease pressure for new regulation and that voluntary design changes could take several years. It can take the government four years or more to approve new regulation.

Joan Claybrook, a former director of the federal auto safety agency and now president of consumer group Public Citizen, says Congress should immediately mandate new rules.

"The industry has known for years about these dangers and has bobbed and weaved to avoid regulation," Claybrook said. "The government has also dropped the ball."

Claybrook was also a fierce critic of industry and government action during the Firestone tire saga in which millions of tires were recalled in 2000 and 2001 after tread separations and blowouts were linked to more than 270 deaths. Most of those tires were standard equipment on Ford Explorer SUVs.

Congress passed landmark auto safety legislation after that investigation.