The National Academy of Sciences will lead a broad investigation into unintended acceleration and electronic vehicle controls under a 15-month study expected to be announced by federal regulators Tuesday.
In addition, the National Highway Traffic Safety Administration will conduct a separate inquiry into sudden acceleration by Toyota Motor Corp. vehicles. Toyota has issued nearly 10 million recall notices worldwide to correct floor mat and gas pedal defects that it says can lead to runaway vehicles.
The two investigations follow pressure from Congress on federal safety regulators to address persistent questions about the causes of unintended acceleration, and whether the problems stem from faulty computer-controlled electronic throttle systems.
At a time when cars are increasingly controlled through complex computer systems, the studies represent the most far-reaching effort yet to assess the causes of sudden acceleration.
"We are determined to get to the bottom of sudden acceleration," Transportation Secretary Ray LaHood said in a news release dated Tuesday. "For the safety of the American driving public, we must do everything possible to understand what is happening."
LaHood also said he had asked his department's inspector general to assess whether federal safety regulators dropped the ball over the last eight years in reviewing thousands of motorist complaints about sudden acceleration.
The two studies are expected to cost about $3 million combined.
In recent congressional hearings, the performance of those regulators came under severe criticism, based on concerns that they lacked expertise to examine automobile electronics and depended too much on the industry to police itself.
LaHood said his department's inspector general would determine whether NHTSA's Office of Defects Investigation has sufficient resources and technical expertise.
The National Academy of Sciences' investigation will be conducted by its National Research Council, which will tap a panel of experts that will study electronics in vehicles of all manufacturers, human error, mechanical failure and accelerator systems.
A second study focused on Toyota vehicles would be conducted by NHTSA, which is enlisting help from NASA. The space agency was brought into the probe for its "expertise in electronics, hardware, software, hazard analysis and complex problem solving," the Transportation Department announcement said.
The NHTSA effort, which is supposed to be completed by late summer, will try to determine whether Toyota vehicles "contain any possible flaws that would warrant a defect investigation."
NHTSA is currently reviewing its past defect investigations but does not have any formal investigation or inquiry into whether Toyota electronics could be causing sudden acceleration.
Sean Kane, president of Safety Research & Strategies, said the studies are "a step in the right direction," particularly the appointment of an independent panel under the National Research Council and the investigation requested by the inspector general.
Although Toyota has acknowledged that its vehicles have mechanical defects that could cause sudden acceleration, it has repeatedly asserted that there are no known defects in its electronic throttle systems.
In addition to its own examination of its electronic systems, the company has hired the technical consulting firm Exponent Inc., which issued a preliminary report also asserting that no evidence pointed to any defect in the electronics.
But complaints about sudden acceleration in Toyota vehicles began to rise in 2002, The Times reported last year. That's when the company introduced an electronic throttle that links the driver to the engine through sensors, microprocessors and wires.