Federal highway safety inspectors have found that the Lexus ES 350 sedan involved in a crash that triggered Toyota's largest recall had an accelerator pedal design that could increase the risk of its being obstructed by a floor mat.

The Los Angeles Times noted that Toyota had previously said that the floor mat was improperly installed and may have trapped the accelerator pedal, causing the vehicle to race down a highway in suburban San Diego at over 100 mph before crashing and bursting into flames, killing an off-duty traffic policeman and three members of his family.

The paper said the latest report on the crash by the National Highway Traffic Safety Administration drew no conclusions about the cause of the 28 August accident but disclosed new details, including the fact that the brakes were heavily damaged, apparently confirming a 911 call made by the driver's brother-in-law from the speeding car, during which he said, "There's no brakes."

The Times reviewed NHTSA documents in a past investigation of Lexus vehicles which, it said, showed that the agency had found that the Lexus ES braking system loses power assist when the throttle is fully opened, increasing braking distance five-fold.

The new report also indicated that the Lexus' accelerator pedal design may have contributed to the risk of floor mat entrapment.

"Beyond the main pivot, the lever is not hinged and has no means for relieving forces caused by interferences," investigators found.

Toyota has said that among the remedies it is considering in the current recall is an adjustment to the pedals or their design.

The report also noted that the lower edge of the accelerator pedal was "bonded" to the rubber floor mat, shown in a grainy photograph. The photograph also showed damage to the area of the floor mat surrounding the accelerator pedal.

Saylor owned a different Lexus that was being serviced and was given the 2009 ES 350 as a loaner car the day of the accident. Toyota has indicated that the dealership incorrectly installed the mats.

Investigators found the car had rubber all-weather floor mats for a Lexus RX400h SUV and that they were unsecured by the vehicle's retaining clips.

Toyota had previously stated that the mats were for a different Lexus vehicle, but had not said which model.

The NHTSA report found that one of the two clips on the Saylor vehicles had pulled out of the carpeting and was lying under the floor mat. The other clip was still attached to the carpeting, but not hooked into the floor mat.

The vehicle's brake surfaces showed signs that they had been worn down through heavy braking against the full force of the 272hp engine.

Investigators also noted that instructions for operating the car's keyless ignition, which required that the power button be pressed for three full seconds to turn off the engine while the car was moving, were "not indicated on the dashboard".

Last month, Toyota announced a 3.8m vehicle recall and asked owners of affected models to remove their floor mats until a permanent remedy was devised.

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