Closed-loop traffic control systems can be operated by either Time-of-Day (TOD) mode or Traffic Responsive Plan Selection (TRPS) mode. When properly configured, the TRPS mode has the potential to provide an optimal operation due to its ability to accommodate abnormal traffic conditions such as incidents, special events, and holiday traffic. TRPS mode can also reduce the need for frequent redesign/updates to signal timing plans. To date, there have not been any formal guidelines for selection of robust and optimal TRPS system parameters and thresholds. Consequently, traffic engineers usually revert to the TOD mode of operation for its ease of setup. This report provides a new methodology for robust and optimal selection of TRPS parameters and thresholds. The report presents an innovative framework of TRPS system setup following a comprehensive approach that incorporates a multi-objective evolutionary algorithm and a supervised discriminant analysis. The developed guidelines are presented in simplified tables to facilitate their implementation. Guidelines were verified by using hardware-in-the-loop simulations. Compared to just the worst possible solutions encountered during the optimization, the final solution provided a concurrent savings of 53 percent in delay and 19 percent in stops.

This handbook, which was developed in recognition of the need for the compilation and dissemination of information on advanced traffic control systems, presents the basic principles for the planning, design, and implementation of such systems for urban streets and freeways. The presentation concept and organization of this handbook is developed from the viewpoint of systems engineering. Traffic control studies are described, and traffic control and surveillance concepts are reviewed. Hardware components are outlined, and computer concepts, and communication concepts are stated. Local and central controllers are described, as well as display, television and driver information systems. Available systems technology and candidate system definition, evaluation and implementation are also covered. The management of traffic control systems is discussed.

Traffic responsive plan selection (TRPS) control is considered an effective operational mode in traffic signal systems. Its efficiency stems from the fact that it can capture variations in traffic patterns and switch timing plans based on existing traffic conditions. Most of the research performed to date has focused on either small traffic networks-with up to five intersections-or theoretical networks. Past research has also focused on the threshold mechanism implemented in the National Electrical Manufacturers Association (NEMA) traffic controllers. There is very limited research on the pattern-matching mechanism implemented in the 170 controllers. This report documents a new approach to generating traffic scenarios for large networks, addressing issues such as the unequal traffic distribution and the large combination of traffic movements from multiple intersections. This approach is based on the selection of significant critical movements controlling the network using statistical correlation analysis of actual detector data and the use of synthetic origin-destination analysis of the entire network. The proposed approach was applied in the design of the traffic responsive control mode for the Reston Parkway arterial network, which has 14 intersections. Detector data were used to validate the results of the proposed approach. The validation process showed that the traffic system was correctly modeled and sufficiently represented by the proposed approach. Multi-objective optimization was used to generate the final timing plans and the TRPS pattern-matching parameters. Simulation analysis revealed that implementation of the traffic responsive control mode in the Reston Parkway network can achieve an average delay reduction of 27 percent and an average stops reduction of 14 percent on weekends and an average delay reduction of 18 percent and an average stops reduction of 21 percent on regular week days. The methodology documented in this report should be followed to implement TRPS control on large arterials in an optimal and stable manner. Optimal and stable operation of TRPS could significantly reduce congestion while capitalizing on existing traffic control infrastructure with a 46:1 benefit-cost ratio.

This "Traffic Control Systems Handbook" updates the 1985 edition (FHWA-IP-85-11; TRIS 00475445) and broadens the scope to include Intelligent Transportation Systems (ITS) technology and concepts. The Handbook recommends decision-making processes in selection, implementation and operations of a traffic control system and describes ITS plans and programs. The "Traffic Control Systems Handbook": serves as a basic reference in planning, designing and implementing effective traffic control systems; provides an updated compendium of existing traffic control technology for the advanced designer and user; describes existing and evolving traffic control system technology; and aids understanding and facilitates training in the traffic control system field.