Automatic detection of incidents on a freeway traffic management system (FTMS) can be thought of as two distinct tasks. The first is the detection of congestion and the second is the determination of whether or not the congestion is incident related. Development and testing of the congestion detection task for a new incident detection algorithm for an ftms are described. A new logic has recently been proposed for the determination of whether congestion is recurrent or incident caused. The congestion detection logic uses flow, occupancy, and speed (if available) from a single station to automatically detect congestion near that station. This logic has been subjected to on- and off-line tests on a system on which congestion is largely incident related. The results show a good false-alarm rate and a high detection rate, with some incidents detected earlier than they were identified by FTMS operators.
Abstract