ESTIMATION OF INSTANTANEOUS TRAVEL TIMES FOR HONG KONG REAL-TIME TRAVELLER INFORMATION SYSTEM

This paper presents a real-time traveler information system (RTIS) for Hong Kong, which estimating instantaneous travel times using automatic vehicle identification (AVI) data. The system is a robust on-line updating platform for advanced traveler information, from which the real-time travel time estimates for Hong Kong road networks can be easily extracted. In the RTIS, the travel times are estimated by the real-time AVI data, the off-line travel time estimates and their 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 variance-covariance matrices are obtained from a traffic flow simulator. On the basis of integration of these real-time and off-line traffic data, the current traffic conditions on Hong Kong major roads can be estimated at five-minute intervals. A case study is carried out in Kowloon Central urban area to collect observed data for validation of the results of the proposed RTIS.