Adaptive cruise control (ACC) systems regulating headway and speed for freeway and rural highway driving are just entering the market in the latest vehicle series. In the future, it is also desirable to utilize the advantages of this technology under the complex conditions present in urban areas or even in city traffic. Especially congestion, with its attendant high fuel consumption and loss of time, offers an enormous potential. In addition to reducing the driver's burden of repeated acceleration and braking and improving driving comfort, assistance systems will also improve traffic efficiency and safety by creating steadier traffic flow and a more homogeneous vehicle headway distribution. These improvements will allow more rapid dissipation of congestion and reduce the risk of rear end collisions.
The extension of ACC systems planned for the development of the Congestion Assistant will concentrate on driving in jammed traffic – i.e., at low or zero speed and high vehicle density. For these situations, the assistance system will be designed to provide the driver with both longitudinal and lateral guidance. Using appropriate simulation techniques, the project will also investigate whether and to what degree traffic flow can be further improved using inter-vehicle communication. In addition to the indirect fuel savings due to smoother flow, the potential for fuel savings resulting directly from optimized driving systems will also be investigated.
Initially, a coordinated concept will be created for a congestion assistant designed to reduce the burden on the driver and improve driving safety. This concept will be developed on the basis of detailed, systematic investigations of driving situations and driver behaviour in congested traffic, coupled with an analysis of user needs and preferences as well as the acceptance of different forms of driver support. An appropriate sensor fusion concept will be designed as well as a new controller, based on a combination of theoretical insights, simulation results, and empirical testing in practice. Furthermore a transparent user interface will be designed taking into account both technical considerations as well as driver abilities. The results could serve as a basis for future national and international standards.