AbstractTo enable the safe and fast formation of connected automated vehicle (CAV) platoons in real-world traffic, a preceding vehicle identification system for mixed traffic (PVIS-mixed) is proposed. PVIS-mixed utilizes the vehicle’s radar measurements and global positioning system (GPS) measurements reported by surrounding connected vehicles to find the communication identity of the preceding vehicle. The design of PVIS-mixed is based on three goals: a low probability of making a wrong identification, a low probability of missing the connected preceding vehicle, and short time consumption of the identification procedure. The proposed PVIS-mixed is evaluated in highway traffic simulated by real vehicle trajectory data from the Next Generation Simulation (NGSIM) program. Evaluation results showed that the performance of PVIS-mixed is not related to the adoption rate of connected vehicles, and 1 m is found to be the required relative positioning accuracy to make 99th percentile time consumption <10 s. It was observed that the multipath bias of GPS positioning could affect the usability of CAV platooning. The possible solutions are then discussed as future work.