This paper describes the conversion of the UK National Motorway Communications System from its first generation system (NMCS1) to its second generation system (NMCS2). It was clear by the mid-1980s that NMSC1 would need replacing. The new system, NMCS2, had to be distributed to enable it to support new telematics systems. It was also necessary to extract the maximum economic life out of NMCS1 while introducing NMCS2. The conversion to NMCS2 had to be manageable and transparent to operators and travelling drivers. Strategies needed to be flexible but robust, as the implementation would take several years and be liable to changing policy objectives. NMCS2 is based on the GOSIP open systems architecture and supports the existing functionality for motorway matrix signalling and emergency road telephones. The architecture covers outstations and inter-control office connections, and also instations; it is designed for UK interoperability and compatibility with other systems. The paper also covers the procurement and implementation strategies adopted, and provides an insight into the experience gained from managing complex parallel developments in a real-time traffic control environment. It discusses the value-for-money approach, taken to the purchase of control offices, and the savings made.
Abstract