Alabama DOT deploys queue detection system in Tuscaloosa work zone

April 29, 2019

State DOTs have been increasingly deploying intelligent transportation systems (ITS) in work zones over the last 10 years with the goal of improving traffic operations and safety by providing real-time information to the traveling public.

After the widening of I-20/I-59 in Tuscaloosa, Ala., began, traffic conditions worsened with long queues, secondary crashes and extreme delayed travel times, so Alabama DOT (ALDOT) officials turned to technology to help mitigate the issues. Work Area Protection teamed with Ozark Traffic Management LLC to deploy a queue detection system consisting of high-definition radars and cameras, full matrix LED message boards, and Bluetooth detectors. The team fully integrated the system into the Computer Highway Information Processing System (CHIPS), which is a patented software/web-based system where you can control, track and monitor all the ITS field devices.

Trailer-mounted high-definition radar units that monitor lane-by-lane speed, volume of passing cars, density of traffic and classification of vehicles are placed approximately every half mile throughout the work zone. Whenever traffic speeds drop below a certain threshold determined by the traffic engineers, automated messages are then triggered to post on the full matrix LED message boards upstream of the slowed zone to alert incoming travelers of the conditions ahead so they may make an informed decision on which route to take. In addition to the queue detection, Ozark Traffic and Work Area Protection deployed high-definition cameras every mile throughout the work zone to monitor traffic conditions and more effectively manage incidents. Bluetooth detectors also were placed at the exits and along the detour route to give accurate travel times throughout the work zone. All the ITS devices report to the central software where the ALDOT Traffic Management Center staff can view the conditions and make operational changes as needed.

Ozark Traffic Management LLC’s trained staff continually monitors the system for failures and makes routine maintenance visits to ensure the queue detection’s reliability. In coordination with the prime contractor and ALDOT, Ozark Traffic Management responds in a timely manner to incidents involving trailer-mounted devices to bring them back to working order as soon as possible.

With the amount of data being collected and delivered by the CHIPS software throughout the project, ALDOT and their consultants will be able to analyze traffic patterns and the results of having the smart work zone in place. ALDOT will be able to use this information along with the Federal Highway Administration’s Smart Work Zone scoring guidelines to determine future deployments and potential increases in hours of operations for the prime contractors.