Operating at the interface

In January 1995, a new motorway bridge, carrying the M3 motorway over the River Laggan, was opened in Belfast, Northern Ireland. On its approaches, there are eight signalised interchanges, linked to the urban road system within 6km. This paper describes the motorway control system around the bridge, which is based on UK Highways Agency (HA) specifications. The system has an open architecture with a Control Office Base System (COBS) controlling the data flow to individual subsystems. It was the first COBS to be implemented in the UK, and its final design allowed for specific traffic management issues requiring control facilities. Its subsystems include those for message signs, automatic incident detection, ramp metering, and communications to the Belfast urban traffic control (UTC) system. This paper first discusses current progress on the project. It then considers the project's institutional, functional, motorway/urban, operational, and strategic interfaces. It finally outlines possible future developments. The system already has greater operational flexibility, and it is intended to study how its flexibility can be increased, mainly by incorporating a multimodal interface within the UTC system. The possibility of extending the system to other parts of the motorway network is being investigated. For the covering abstract, see IRRD E100187.