Representatives of the National Highway Traffic Safety Administration told members of Congress that brakes weren't applied in 35 of the 58 cases they reviewed -- suggesting motorists hit the accelerator when they intended to apply the brake pedal.

The preliminary findings, based on so-called black box data taken from vehicles, may bolster Toyota Motor Co.'s long-held assertion that there is nothing wrong with its cars' electronics. Toyota maintains that motorists or mechanical glitches are responsible for thousands of reports of unintended acceleration.

The results are not definitive and NHTSA and other agencies are continuing to investigate.

Safety advocates argue that the data is just one aspect of the investigation, and that sudden acceleration incidents due to electronic faults may occur in cases in which the auto black box recorded nothing.