Test and Evaluate a Bluetooth Based In-Vehicle Message System to Alert Motorists in Work Zones


Chen-Fu Liao

May 2019

Report no. CTS 19-09

Safe and efficient traffic flow in a work zone is a major concern for transportation agencies. To reduce risky behavior around work zones, 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. Our previous effort focused on an inexpensive technology based on Bluetooth low energy (BLE) beacons that can be deployed in or ahead of the work zone. A smartphone app, called WorkzoneAlert, was developed to trigger non-distracting, auditory messages in a smartphone mounted in a vehicle within range of the BLE beacons. Messages associated with BLE beacons around the work zone can be updated remotely in real time and thus could provide significantly improved situational awareness about dynamic conditions in work zones, such as awareness of workers on site, changing traffic conditions, or hazards in the environment. We incorporated the recommended in-vehicle message elements and user interface from a human factors study previously conducted by the HumanFirst lab and deployed the in-vehicle work zone information system at three construction sites (CSAH 53, CSAH 112, and MN-65) in the Twin Cities metropolitan area (TCMA). Our field test results indicated that the WorkzoneAlert app is able to reliably detect the BLE beacon placed an average of 127 m away on traffic signs or portable radar speed signs and successfully announce the corresponding message associated with each BLE beacon.

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