Application of automatic vehicle identification technology for real-time journey time estimation

This paper presents a real-time traveler information system (RTIS) for journey time estimation using automatic vehicle identification (AVI) data in Hong Kong. This RTIS can also deduce the travel times on the other road links without real-time AVI data. The travel times, in RTIS, are estimated by the real-time AVI data, the off-line travel time estimates and the related spatial variance–covariance relationships between road links. The real-time AVI data adopted for RTIS are Autotoll tag data in Hong Kong; whereas the off-line link travel time estimates and their spatial variance–covariance matrices are obtained from a traffic flow simulator. By integration of these real-time and off-line traffic data together, the travel times on the road links either with or without real-time AVI data can be updated at 5-min intervals. Validation of journey time estimates is carried out at various selected paths in Hong Kong urban area. The results show that the performance of RTIS on real-time journey time estimation in Hong Kong is satisfactory and acceptable.