Evaluation of Small City Traffic Signal Network

IN T R O D U C T IO N Small cities have minor traffic congestion which occurs on major arterials. Primarily because of the importance of the central business district (C B D ), the greatest traffic delays result from the morning, noon and evening peak flows to, from and through the city center. In addition, the points within any size urban area of highest vehicle delay are at the signalized intersections. It follows then that the places where significant improvements could be achieved are in the network of traffic signals located downtown. One constraint in what small cities can accomplish in the way reducing CBD congestion is and will continue to be financial. As a result, physical changes in the street system are not considered until every effort is expended in improving the efficiency of the existing sys­ tem. In some instances improvements can be achieved through the removal or other adjustments in the regulation of parking. The TO PIC S program is aimed at optimal use of the existing street system. Because of the financial problems of small urban areas and the installation costs of coordinated traffic control systems, it becomes essen­ tial to fully evaluate the impact and economic consequences of such an installation. This was the purpose of the research reported here. In recent years the flexible coordinated traffic signal system has been acclaimed as the ultimate in moving traffic efficiently. This is the signal system with a brain; no longer is the traffic engineer tied to a pre-timed three dial local controller. He can now have the system in effect that meets the instantaneous demand most efficiently through vehicle detection, computerization and interconnection. This is good, but can this system be used effectively and economically in the small to medium-sized city? Do the demands vary enough in the small city