Unintended Vehicle Acceleration Expert Article

Through the course of our casework we have seen numerous cases involving claims of unintended vehicle acceleration. Whether our investigation determined that the cause was electrical, mechanical, or human error, in many of these incidents there were steps that a well informed driver could have taken to safely bring their vehicle to a stop.

In this short article, our automotive engineers share their expert insight on what you should do if you find yourself in an incident with unintended acceleration.

Unintended Vehicle Acceleration

Handling Unintended Acceleration Like an Expert

Given the complexity of modern vehicles and the quantity of vehicles on the roads, we expect that we will continue to see incidents of unintended acceleration well into the future. While most drivers will never encounter this phenomenon, it is best to be prepared should you find yourself in a dangerous situation.

The first and hardest step to follow, is to not panic. In the majority of situations it is possible to bring a vehicle experiencing unintended acceleration to a safe stop by following these steps:

  1. Brake - Press the brake pedal firmly. Do not pump the brakes; instead keep steady, hard pressure on the pedal. Pumping the brakes will cause you to lose vacuum boost, and overheat the brake pads, making it harder to brake. The brakes can out-power the engine in even high horsepower cars, as long as you don’t overheat them through multiple applies (pumping).
  2. Shift into Neutral - Both manual and automatic transmission cars can be shifted into neutral while moving. The engine may rev, however most vehicles have rev-limiters to protect the engine. Besides, your safety is more critical than the longevity of your engine.
  3. Bring the Car to a Stop - Pick a safe location, out of the travel lanes if possible. Gently guide the vehicle to the safest location. Do not make sudden steering inputs, this could result in a loss of control. Shut the car off and shift into park, or neutral for manual transmissions, and apply the parking brake.

If you are unable to bring the car to a stop using steps 1 and 2, as a last resort, shut the engine off using the ignition switch. This will cause a loss in power steering and power brake assistance; however, these systems will still function with higher efforts required. The airbag system may also be disabled when shutting the engine off. Be careful to only turn the ignition switch back one position when shutting off the engine in order to avoid the ‘lock’ position. If the ignition switch is rotated to the Lock position steering control will be lost. Many new cars with push button start require holding the button 3-4 seconds in order to shut off the engine while moving. Check your vehicle’s Owner’s Manual to be sure of how to shut your vehicle’s engine off while moving.

Investigating Incidents of Unintended Acceleration

From an engineering standpoint, there are many systems and components that can contribute to unintended vehicle acceleration. Best practice is to preserve evidence and involve an automotive engineer early in the process. To effectively determine the cause of a crash, it may be necessary to review several different aspects of the vehicle and incident scene, including:

  • Event Data Recorder (EDR) download
  • Investigation of crash scene for skid marks and other clues
  • Inspection of interior, powertrain, and exterior of vehicle
  • Inspection of brake light bulbs for evidence of hot shock
  • Witness statements regarding brake light status, engine revving, etc.
  • Vehicle maintenance and inspection records

Need More Information?

Contact our experts directly to discuss your case and how we can help. Our automotive engineers have experience investigating these incidents and can help you by conducting a thorough and efficient investigation.

Featured Expert

Marcus A. Mazza, Automotive Engineer & Crash Expert

Marcus A. Mazza, P.E.

Automotive Engineer & Crash Expert
Marcus Mazza is an automotive engineer with diverse experience in production vehicles, military vehicles, and motorsports. He applies his expertise to intellectual property disputes as well as vehicle… read more.


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