Assessing Driver Understanding and Responses to a Visual and Audible Work Zone Intrusion Alarm System

Oldcastle Materials and ARTIS, LLC joined forces to develop an innovative work zone intrusion detection and alarm system. The system flashes LED lights and emits an audible alarm if an intrusion is detected. TTI conducted a study to assess how motorists approaching a simulated work zone with an alarm system interpreted the lights/alarm and responded to them. A demographically-balanced group of 63 participants drove an instrumented vehicle around a test course created at the Texas A&M University RELLIS Campus. Several vehicle operating measures were recorded, and participants were asked questions at the end of the study to understand their thoughts about what the alarm meant and what a driver should do in response to the alarm. Overall, very few statistically significant changes in vehicle operating measures were recorded when the alarm system was activated, suggesting that the system did not have an adverse effect on driver behavior. Participant responses to questions indicated a common perception that the alarm was initiated to get them to slow down, which is one of the desired outcomes of the system. However, many of the participants perceived the alarm as a police or emergency vehicle presence nearby, and believed that they should have pulled over and stopped when the alarm activated. Based on these findings, the researchers recommended that the audible alarm be modified to provide short bursts (less than one second long) to differentiate it from emergency response sirens.