A traffic flow simulator for short-term travel time forecasting

This paper presents an off-line forecasting system for short-term travel time forecasting. These forecasts are based on the historical traffic count data provided by detectors installed on Annual Traffic Census (ATC) stations in Hong Kong. A traffic low simulator (TFS) is developed for short-term travel time forecasting (in terms of off-line forecasting), in which the variation of perceived travel time error and the fluctuations of origin-destination (O-D) demand are considered explicitly. On the basis of prior O-D demand and partial updated detector data, the TFS can estimate the link travel times and flows for the whole network together with their variances and covariances. The short-term travel time forecasting by O-D pair can also be assessed and the O-D matrix can be updated simultaneously. The application of the proposed off-line forecasting system is illustrated by a numerical example in Hong Kong.