The CIRCLES (Congestion Impacts Reduction via CAV-in-the-loop Lagrangian Energy Smoothing) Consortium, comprising Vanderbilt University, UC Berkeley, Temple University and Rutgers University-Camden, in coordination with Nissan North America and Tennessee Department of Transportation, recently concluded a five-day open-track experiment testing an artificial-intelligence-equipped cruise control system designed to increase fuel savings and ease traffic using 100 specially equipped Nissan Rogue vehicles.

The CIRCLES project aims to reduce instabilities in traffic flow, called phantom jams, that cause congestion and waste energy.

The experiment—which ran 14 Nov. through 18 Nov. on a sensor-filled portion of US Interstate 24——is based on results from an earlier, closed-track study. Findings indicated a single AI-equipped vehicle influenced the speed and driving behavior of up to 20 surrounding cars, causing a positive ripple effect to help smooth human-caused traffic congestion.

The CIRCLES Consortium will spend the next several months analyzing data collected on the AI-equipped vehicles and their impact on the flow of traffic over the duration of the experiment.

The test was conducted on the recently opened I-24 MOTION testbed, the only real-world automotive testing environment of its kind in the world. Stretching four miles just southeast of downtown Nashville, the smart highway is equipped with 300 4K digital sensors capable of logging 260,000,000 vehicle-miles of data per year.

The CIRCLES Consortium research is funded by the National Science Foundation and US Departments of Transportation and Energy. Support was also provided by Toyota North America and General Motors. The experiment included two additional test units:Toyota RAV4 and Cadillac XT5.

On 16 November alone, the system recorded a total of 143,010 miles driven and 3,780 hours of driving. The I-24 MOTION system, combined with vehicle energy models developed in the CIRCLES project provided an estimation of the fuel consumption of the whole traffic flow during those hours.