This study sought to evaluate three existing Work Zone Intrusion Alert (WZIA) technologies: Intellicone; Advanced Warning and Risk Evasion (AWARE); and the Worker Alert System (WAS). Intellicone is an impact-activated system that utilizes traffic cone mountable sensors and Portable Site Alarms (PSA). AWARE is a radar-based warning system that marks a vehicle as an intruder if it is traveling at a speed higher than the speed limit. One version of AWARE, the Sentry, was evaluated; it consists of a sensor unit with a radar, LEDs, an alarm, and personal alarms (called Worktraxs). WAS is a pneumatic sensor-based technology with a pneumatic trip hose sensor, signal transmitter, Portable Alarm Case (PAC), LEDs, and Personal Safety Devices (PSDs).
A two-phased evaluation approach was used to assess the technologies. Controlled tests were conducted in November 2019 along a section of TN-14; these systems were evaluated on system accuracy, efficacy, and coverage. Live tests occurred in December 2019, August 2020, and December 2020 along TN-195 in Williston, Fayette County and various locations in Shelby County. AWARE was assessed on driver reactions and workers’ perceptions of user-friendliness. Intellicone and WAS were both evaluated on user-friendliness, worker reactions and preferences, and system effectiveness. Responses from workers in the live tests were collected using on-site surveys.
The report presents the following recommendations on suitable use cases for three selected WZIA technologies based on multicriteria analysis consisting of capital cost, performance accuracy, safety aspects, easiness of operation, and life cycle cost.
Overall, all three WZIA systems were found to be user-friendly, easy to install and use, and durable. AWARE was perceived to be more effective and beneficial (100 percent of workers) than WAS (89 percent) and Intellicone (88 percent). AWARE was also the most durable and the least likely to raise false alarms.
- Consider deploying Intellicone on construction work zones on major highways since it can be highly beneficial and is best suited for lane closures longer than 1,000 ft long and for closures maintained for several days with an unlimited transmission range.
- Intellicone has good work zone coverage, distinct and loud alerts, and a low life cycle cost. However, the setup is time consuming, and there are issues with false positive and negatives and with connectivity. As of December 2021, this technology is not available in the United States.
Advanced Warning and Risk Evasion (AWARE) Sentry
- AWARE has good work zone coverage, distinct and loud alerts, accurate intrusion detection, and a quick setup.
- AWARE Sentry for flaggers is highly effective when used for flagging operation by flaggers, but it requires a smartphone application to configure the settings and has a high life cycle cost. It is suggested for use only on short-term work zones where it can be removed and stored safely after completion of work.
Worker Alert System (WAS)
- WAS has multiple alert sounds, a low life cycle cost, and a quick and easy setup. However, the transmission range is limited, transmission lags reduce usefulness for workers close to traffic, and the system does not support live tracking of devices.
- WAS is ideal for use in short-term work zones that are not too close to the traffic. The evaluation results suggest deploying WAS for short term repair projects less than a day long on shoulders without lane encroachment, mobile work zones, and highways with speeds less than 30 mi/h.