Test and Evaluate a Bluetooth Based In-Vehicle Message System to Alert Motorists in Work Zones
Chen-Fu Liao, Senior Systems Engineer, Mechanical Engineering
According to work-zone injury and fatality data published by the USDOT, more than 20,000 workers are injured in work zones each year. Many ITS tools and applications have been developed and implemented to effectively mitigate traffic impacts caused by roadway construction. We have developed a prototype system to investigate the feasibility of using in-vehicle messages to increase drivers' awareness of safety-critical and pertinent work-zone information. Inexpensive Bluetooth Low Energy (BLE) tags were deployed in or ahead of a work zone. A smartphone app was also developed to trigger less-distracting auditory messages from a smartphone or a vehicle's infotainment system when the drivers are approaching a work zone. We deployed several BLE tags and conducted field experiments at two work zones (CSAHs 53 and 112) in Hennepin County, Minnesota. We tested the app running in the background on a smartphone using a sedan and a minivan at different times of day and different days of the week to evaluate the system performance. The vehicle location and the timing of each triggered message were logged for data analysis. On average, the work-zone alert system was able to detect the BLE tag and announce associated auditory message when a vehicle is 106 meters (348 ft) ahead of the work zone at CSAH 53 site. Similarly, the results from the CSAH 112 site has an average BLE detection range of 167 m (548 ft). The results indicated that our system is capable of providing timely warning messages to alert motorists approaching work zones.