Abstract
The purpose of this paper is to review some of the main Operations Research (OR) and Artificial Intelligence (Al) research achievements in the field of traffic engineering, with particular reference to road traffic control. Therefore, the performances of the discussed approaches are illustrated and compared with respect to the features and the requirements which characterize some of the most relevant problems in the area of interest. The potential for a combined use of typical OR and Al methods and techniques when solving complex real-world, large-size traffic control problems is also emphasized. Finally, some concluding remarks are drawn that highlight the new challenges awaiting for the scientific community efforts.