Consumer groups say the government's decision raises questions about how seriously regulators take their own rollover test.

Among other things, the act orders the safety administration to conduct real-world rollover tests.

The automakers have argued, though, that rollover tests do not produce consistent results.

The rollover test is a series of sharp swerving maneuvers done at escalating speeds.

The Tread Act, passed in 2000, directed the traffic safety agency to create a rollover test and ratings.

More recently dynamic rollover tests have been proposed as opposed to static crush testing (video).

Still, European automakers, and particularly Volvo, have long conducted more stringent rollover tests.

The announcement came a week after regulators said the vehicle's suspension had broken during new federal rollover tests.

This year, the traffic safety agency has been conducting its first rollover tests on a track.

Not that any of that helped on the government's rollover test.