The Congestion Impacts Reduction via CAV-in-the-loop Lagrangian Energy Smoothing (CIRCLES) consortium, which consists of Vanderbilt University, UC Berkeley, Temple University and Rutgers University-Camden, working in coordination with Nissan North America and the Tennessee Department of Transportation, has concluded a five-day open-track experiment.
During the experiment, which ran between November 14 and 18, 2022, the team used 100 Nissan Rogue vehicles to test an artificial-intelligence-equipped cruise control system designed to improve fuel savings and ease traffic congestion.
The test was based on the earlier results of a close-track test and was carried out on a sensor-filled portion of US Interstate 24. The recently opened I-24 Motion testbed is claimed to be the only real-world automotive testing environment of its type globally and covers a 4-mile stretch southeast of downtown Nashville, Tennessee. The smart highway features 300 4K digital sensors that can capture 260,000,000 vehicle-miles of data annually.
Upon completion of the test, results showed how a single AI-equipped vehicle influenced the speed and driving behavior of up to 20 surrounding cars. A positive ripple effect was created, which helped reduce human-caused traffic congestion.
Over the coming months, the CIRCLES consortium will continue to analyze data collected from the AI-equipped vehicles and their impact on the flow of traffic during the test.
Funded by the National Science Foundation and US Departments of Transportation and Energy, the CIRCLES consortium also tested a Toyota RAV4 and Cadillac XT5 with support provided by Toyota North America and General Motors.
“On November 16 alone, the system recorded a total of 143,010 miles driven and 3,780 hours of driving,” said the CIRCLES team in a joint statement. “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. The concept we are hoping to demonstrate is that by leveraging this new traffic system to collect data and estimate traffic and applying artificial intelligence technology to existing cruise control systems, we can ease traffic jams and improve fuel economy.”
“When it comes to transportation and mobility in Tennessee, we are at a critical juncture,” explained Butch Eley, deputy governor and TDOT commissioner. “Traffic congestion is now becoming more prominent throughout Tennessee, and not just in urban areas. Addressing these challenges will force us to think critically about solutions, as transportation infrastructure projects traditionally are not identified or completed before traffic congestion more dramatically affects our quality of life. One of these solutions is greater use of technology to enhance mobility.”
“The I-24 Motion project is a first-of-its-kind testbed, where we’ll be able to study in real time the impact connected and autonomous vehicles have on traffic in an open road setting,” said Meredith Cebelak, adjunct instructor of civil and environmental engineering and transportation and transportation systems management and operations department leader at Gresham Smith. “The permanent infrastructure has been designed and installed, meaning the testbed will always be ‘on’ and available to researchers. By unlocking a new understanding of how these vehicles influence traffic, vehicles, infrastructure and traffic management strategies, design can be optimized to reduce traffic concerns in the future to improve safety, air quality and fuel efficiency.”
