Power Steering Assist Failures

Drivers learn to trust the systems in their vehicles and do not anticipate failures. The objective of this study was to investigate whether or not drivers can safely handle a vehicle when there is a sudden, unexpected shut down of power assisted steering. Forty drivers, ten in each of four vehicles, drove on a controlled road. Results indicated that the majority of drivers could not safely complete a low speed right turn when power assisted steering suddenly failed in a cornering scenario. Drivers viewed this as a dangerous safety issue and indicated that the risk of such a failure was unacceptable. Results highlight the importance of including real users in safety assessments to gain a more accurate understanding of the consequences of vehicle system failures. They also shed light on some potential challenges for automation failures on future vehicle systems.