Performance measures included speed profiles, braking, deceleration and lateral position and differences were examined statistically between treated and control sites on the road and in the simulator. The results showed that speed and braking responses were correlated for most sites and that lateral placement results were similar for curves. In addition, while there were consistent speed reductions in both test environments, they were more pronounced in the simulator than on the road. A second simulator trial showed that rumble effects enhanced the visual perceptual effects of these treatments, although further research is warranted to test this more rigorously. Importantly, though, the validation study confirmed that the simulator is a suitable test environment for evaluating perceptual countermeasures, especially when testing for speed reductions, and to a lesser degree braking, as the principal dependent measures.
Lateral placement is a valid measure of curve driving performance.