Cooperative Intersection Collision Avoidance System (CICAS): Signalized Left Turn Assist and Traffic Signal Adaptation

The Cooperative Intersection Collision Avoidance (CICAS) program is a multi-year, cooperative research program including federal, state, academic, and industry partners. The goal of the research program is to use ITS technologies to address the problem of intersection crashes. The program is funded through an 80/20 cost share, typically split between the U.S. Department of Transportation (D.O.T.) and a local state D.O.T. The program began in 2003, and has been divided into three functional segments based on crash type. The largest programmatic segment is CICAS-V (Violation) which is led by CAMP, with support from researchers at Virginia Tech, and aims to address the problem of straight crossing path collisions which tend to be the result of stop sign or stop light violators. A second programmatic segment is CICAS-SSA (Stop Sign Assist) which is led by the Minnesota D.O.T., with support from researchers at the University of Minnesota, and aims to address the problems associated with crossing or entering a high-speed, rural road from a stop sign at a minor road. The final programmatic segment is CICAS-SLTA (Signalized Left Turn Assist) which is lead by Caltrans, with support from the California PATH Program (Partners for Advanced Transit and Highways) at the University of California, Berkeley. This CICAS-SLTA segment aims to address crashes caused by vehicles making left turns at signalized intersections where there is no protected left-turn signal. This report focuses on the activities related to the CICAS-SLTA program segment. It builds upon work that was performed during earlier segments (Task Orders 5600, 5601 and 6607) which included the previous Intersection Decision Support (IDS) project and CICAS. The CICAS-SLTA project is currently continuing research in the areas of sensor testing, field data collection, human factors data collection and testing, and warning algorithm design and simulation. The project aimes scheduled to lead to the design of a Field Operational Test (FOT) ready system and detailed FOT work plan, depending on the success of this and a subsequent effort.