Hofmann et al. 2000 : This article presents a system for hybrid adaptive cruise control (HACC) on high speed roads designed as a combination of a radar-based ACC and visual perception. The system is conceived to run on different performance levels depending on the perception abilities. The advantages of a combination of the two sensor types are discussed in comparison to the shortcomings of each single sensor type. A description of the visual lane detection and tracking procedure is given, followed by an overview of the vehicle detection, hypothesis generation and tracking procedure. Afterwards, the assignment of vehicles to lanes and the determination of the relevant vehicle for the longitudinal controller are described.