Comparison of Four Steering Angle and Lateral Position Measures of Driving Performance

Loss of attention leads to less steady driving within the lane and is one of the main causes of road accidents. To improve road safety, steering wheel angle and lateral position are commonly used to objectively assess driving performance, especially in monotonous driving tasks. In the present driving simulator study, 15 participants undertook a boring driving task for 1 hour. Standard deviation of lateral position (SDLP), driving time out-of-lane, average steering wheel angle (Ave steering) and standard deviation of steering angle (SD steering) were continuously measured. The results demonstrated that Ave steering and SD steering are responsive to exactly the same factor(s), and consequently studies should use either Ave steering or SD steering, but not both. While SDLP and out-of-lane are relatively independent of Ave steering and SD steering, they are moderately correlated with each other. Approximately 36% of out-of-lane variance is attributable to factors that are independent of SDLP, Ave steering or SD steering. Future studies of driving performance may benefit from including out-of-lane, as well as SDLP and Ave steering or SD steering.