Work-zone safety ITS: smart barrel for an adaptive queue-warning system

Abstract

A broad concept has been developed for a Work-Zone Safety ITS System that would provide a distributed, queue-warning system that automatically adapts to the current traffic-flow situation in and upstream of the work zone. The core element of the system is be a smart barrel—an ordinary appearing traffic-control barrel containing an inexpensive speed sensor and equipped with a simple, adjustable signaling system and the necessary equipment for communication to a central controller. The study focused on initial investigations of two critical elements of such a system: (1) an inexpensive, but sufficiently capable speed sensor and (2) a simple but effective signaling system. Three prototype speed sensors were developed and evaluated in a limited field study. They used active infrared, passive infrared, and magnetic sensor technologies, respectively. The active infrared system was found to be the most accurate but consumed the most power: an important factor for a device that will be battery-power in the field. The passive infrared system was nearly as accurate and required the least power of the three approaches. Simple signaling schemes were also prototyped and presented to drivers in a pilot experiment using a driving simulator. Both subjective opinions about the utility of the system and objective measures of driving performance were collected. Results suggest that drivers find the adaptive systems more helpful than static road signs and there is evidence for systematic change in their driving performance indicative of enhanced safety.