Area-wide traffic speed-flow model for the Singapore CBD

An area-wide traffic speed-flow model was developed for the Singapore CBD with the aim of providing an analytical framework for the evaluation of traffic management measures for the area (known as the Restricted Zone). A major survey of traffic speed and volume within the CBD was conducted in 1990. The speed data were collected using a fleet of floading cars which moved around two fixed survey circuits for 3 days. In the modelling process that followed, several approaches and mathematical models were studied. The final, recommended model relates journey speeds inside the Zone with the average traffic flow per lane inside the area which, in turn, is correlated with the cordon traffic volume. Thus, the model allows one to estimate average journey speed inside the Zone, based on the total traffic flow crossing the Zone cordon.