Adaptive Cruise Control (ACC) caused dangerous unintended acceleration. This model of vehicle has an ACC that maintains following distance from a leading vehicle. It will decelerate to a full stop and will resume after a full stop while maintaining a proper following distance when prompted by a brief push on the accelerator. At the beginning of this incident, my ACC was set to about 40 MPH and I was following the car in front of me. At a traffic light, I came to a full stop behind the leading car for 10-15 seconds. At this point, I realized that the left lane turn signal changed to green which would allow me to proceed. Since there was no traffic in that lane, I decided to move from my lane to the open left lane. I turned the steering wheel to go around the car in front of me into the left lane. I then briefly touched the accelerator. The result was that the car accelerated at a high pace. Since my foot on the accelerator initiated the event, it took me a second or so to move my foot to the brake and disable ACC. During the acceleration, I was able to steer into the left lane and make the subsequent left turn without incident. I'm unlikely to make this mistake again. However, I'm pretty certain that this sequence is easily repeatable should you want to test for it. This ACC behavior seems dangerous. I expect that resuming ACC while following a vehicle will result in acceleration. But if the car is pointed in a new direction while it is stopped, it seems inappropriate to allow the ACC to resume by tapping the accelerator. A better ACC behavior would disable the"resume after a full stop" functionally if the wheel is turned more that a few degrees after an ACC controlled full stop.
NHTSA ODI 11707542