Time-series forecasts of traffic conditions are recognised as indispensable for optimal operation of the road network. They can also advise the user of the forecast journey time. The robustness of the OPERA system during incident conditions is achieved by physical modelling of the traffic situation, and by data input which is independent from the phenomena occurring within the network. OPERA currently manages a 560km network and 15 variable message signs during the morning peak hour in Glasgow, UK and is being extended to manage the whole Scottish Central Belt primary road network. The system automatically monitors and predicts the traffic flows on the network, analyses incidents and displays information on variable message signs. OPERA uses SIMRES, a macroscopic second-order traffic simulation model. OPERA 2000 is an updated version which incorporates use of recent historic traffic flow profiles updated each week, and updates long-term diversion rates. A similar approach, the MAESTRO system, is being developed in France.
Samenvatting