ABSTRACT
In this paper, we provide a comparison between principles and experience of autonomous or automatic systems on rails and on the street. An automatic metro operates in a controlled and well-defined environment that makes automatic driving possible. Passengers are separated from moving systems, e.g. by using platform screen doors that allow access only directly into the train, which is at standstill. In addition, passengers and third persons are separated from driving trains by fences, tunnels, etc. For road vehicles, currently a large number of assistance system is available that are able to handle specific situations. This leads to the impression that these vehicles can move autonomously. However, these assistance systems are developed in such a manner that the driver must always be able to interfere. There are only some exclusions with genuine autonomously moving vehicles. In general, the environment, in which a road vehicle operates, is much more complex than that of a train, mainly caused by unforeseen situations. We describe differences regarding approval for automated metros, road vehicles and so called Automated Guided Vehicles (AGV). Legal requirements for homologation of road vehicles according to the convention on road traffic are discussed and the implication for the system and the behavior of the driver. We sketch the current technical possibilities for automated driving and the existing technical solutions.
