Congestion in urban areas is often caused by traffic incidents. If such incidents could be quickly detected, preventive measures could be rapidly taken. Drivers can be warned of congestion and incidents using variable message signs. The effect of providing such messages is not widely understood. A system called ASTRID/INGRID has been developed to monitor traffic conditions and detect traffic incidents. ASTRID is an on-line historic database which can store information collected from the SCOOT traffic control system. INGRID is a real-time automatic incident detection system using data from SCOOT and ASTRID. ASTRID and INGRID have been installed in Southampton. An evaluation of INGRID suggests that severe incidents can be detected after 5.5 minutes with a 100% detection rate and 0.5 unconfirmed incident messages per hour. (A)
Abstract