A methodology for assessing driver perception-response time during unanticipated cross-centerline events

Abstract

Objective

The purpose of this study was to present a methodology that utilizes naturalistic driving data to measure the driver response to an unanticipated driving scenario, a cross-centerline event.

Methods

Forward-facing video from naturalistic driving was used to determine when the cross-centerline event occurred. Then, the recorded acceleration and yaw rate data were used to identify the start of braking and steering evasive actions, respectively. A deceleration threshold of −0.1 g was defined as the braking onset, and a yaw rate of 2 deg/s was defined as the steering onset. Perception-response times (PRTs) were derived using these inputs.

Results

17 cross-centerline events were identified from the naturalistic driving database. The drivers in all analyzed events applied the brakes, and 11 of the 17 drivers performed a steering maneuver. However, the average steering PRT (0.39 s) was faster than the average braking PRT (0.84 s).

Conclusions

Based naturalistic data from cross-centerline encroachment scenarios, the average driver steering PRT was faster than the average driver braking PRT. Both the driver’s median braking and steering PRT was faster in these real-world scenarios than in similar test track or simulator studies. Future analyses should investigate which action is attempted first and the effect of time to contact on driver response.

Keywords:

• Perception response time
• evasive action
• cross-centerline
• naturalistic driving study
• SHRP 2

Acknowledgments

The authors would like to thank Mitch Garber and Clay Gabler for their insights and advice for this study.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.