1 Introduction
When designing control systems for rail infrastructures (Harris and Godward 1992, Sussman 2000), designers aim at control strategies that will achieve a cost-effective and appropriate system to transfer passengers safely and reliably. Infrastructure capacity influences the quality of the transport service, not only in terms of reliability, with an infrastructure that provides enough trams/trains to satisfy the demand, but also in terms of safety, where the transport of the required number of passengers can be done in a safe way.