An advanced processing capability based on the use of real-time knowledge-based expert system (kbes) technology to integrate diversetypes of traffic surveillance data for freeway monitoring and control purposes, particularly as part of future "smart roads" projects, is described. One of the major functions of the prototype system is the acquisition and processing of input data drawn from sensors and processes in the real world. The real-time nature of these processes, and the associated need for decision-making information and recommendations, places particular importance on the efficient handling ofdata to avoid unnecessary overloading of the expert system. The relevant types of data include traffic occupancies and volumes from loop detectors in the pavement, information on traffic conditions from closed-circuit television cameras, field reports from police officers and other official personnel, and cellular and emergency telephonecalls from motorists. Emphasis is placed on the way in which the data are acquired, processed, and integrated within a prototype kbes framework to achieve the objectives of the incident management tasks, specifically those of incident detection and verification. Examplesare given of the implementation of these features. This paper appears in transportation research record no. 1320, Freeway operations, highway capacity, and traffic flow 1991.
Abstract