The Congestion Impacts Reduction via CAV-in-the-loop Lagrangian Energy Smoothing (CIRCLES) project aims to reduce instabilities in traffic flow, called "phantom jams," that cause congestion and wasted energy. If you have ever encountered a temporary traffic jam for no apparent reason, this might have been a phantom jam that occurred naturally because of human driving behavior.

Prior work on closed-course testing demonstrated that phantom jams can be reduced using autonomous vehicle technologies and specially-designed algorithms. The CIRCLES project seeks to extend this technology to real-world traffic, where reducing these negative traffic effects could provide ≥10% energy savings.

In 2022, the CIRCLES team conducted the largest open-road traffic experiment of CAVs designed for wave smoothing, in Nashville, TN. The resulting experiment produced news articles with an audience reach of over 1 Billion.

Please visit the CIRCLES website for a comprehensive description of the project, its scope and scale, and resulting data, videos and other products.