The agency's test, which applies pressure to the corners of a vehicle's roof, 'fails to measure the frontal roof area that causes the most harm,' said Joan Claybrook, Public Citizen's president and a former NHTSA chief, at a forum Tuesday that was Webcast. The criticism comes as the U.S. agency prepares to release revised standards for rollover testing by Oct. 1. The groups contend that their own efforts demonstrate 'the need for NHTSA to adopt a similar dynamic test' for cars and light trucks. 'We're in the process of updating our rulemaking and we believe the changes will significantly improve roof strength and safety for the passenger,' NHTSA spokeswoman Karen Aldana said in an interview. 'They are criticizing us before our revised standard is even released.' The vehicles the three groups tested were General Motors Corp.'s 2007 Pontiac G6 car, Chrysler LLC's 2006-model 300 sedan, Toyota Motor Corp.'s 2007 Camry sedan, Volkswagen AG's 2007 Jetta car, Honda Motor Co.'s 2006 Ridgeline pickup and Hyundai Motor Co.'s 2006 Sonata sedan.