Human Factors Issues Related to Use of Vision Enhancement Systems

Vision enhancement systems (VESs) are being developed to improve nighttime driving safety by providing enhanced contrast to drivers. To determine how to evaluate the potential benefits or limitations of such systems, a small-scale investigation of driver performance and behavior with a mockup VES was conducted. To maximize external validity and minimize safety risks, a field experiment was designed and conducted on a closed test track. Four younger observers (ages 26 to 36 years) and four older observers (ages 56 to 70 years) drove an instrumented vehicle and verbally reported the detection and recognition of targets while performing speed monitoring and navigation tasks. Targets near the edges of the lane of travel were detected with and without a mock-up VES and with and without headlight glare. Video recordings of the VES, road scene, driver, and data acquisition screen were obtained. Time code, distance traveled, verbal reports, and gas pedal, brake pedal, and steering wheel measurements were recorded. Results suggested that although the mockup VES provided target contrast at longer preview distances than low-beam headlights alone, the VES enhancements were not always detected by drivers because of the visual, scanning, and cognitive demands of the driving tasks. Also, older drivers were less willing to use the mock-up VES. On the basis of verbal reports, the consensus among all observers was that the VES increased curve detection distances relative to those achieved with low-beam headlights alone. The implications of the study findings for VES use, design, and evaluation are discussed.