RHODES - ITMS TEMPE FIELD TEST PROJECT: Implementation and Field Testing Of RHODES, A Real-Time Traffic Adaptive Control System

RHODES is a traffic-adaptive signal control system that optimally controls the traffic that is observed in real time. The RHODES-ITMS Program is the application of the RHODES strategy for the two intersections of a freeway-arterial diamond interchange. This report addresses the latest phase of the RHODES-ITMS Program that resulted in a field-test in the City of Tempe, Arizona. In summary, this phase involved: (i) the integration of the RHODES logic within the signal controller, (ii) the validation of the RHODES logic using " hardware-in-the-loop " simulation, (iii) the integration of the RHODES algorithms within Tempe's traffic management system, (iv) the deployment of RHODES for the field test and (v) the data gathering and evaluation of traffic performance " with " and " without " the RHODES logic. The objectives of this project were: (i) to see if a communication/computation infrastructure could be designed and implemented for second-by-second detector data collection and signal phase commands, (ii) to see if a traffic-adaptive signal control system could be implemented on an off-the-shelf Advanced Traffic Controller, (iii) to determine whether the RHODES strategy is viable in the field, and (iv) to evaluate the traffic performance of RHODES. The answers for the first three objectives were positive: that is, the communication/computation infrastructure was designed and implemented, and RHODES control strategy was integrated within the infrastructure and proved to be viable. With regard to the fourth objective, RHODES was able to match the performance of the current well-tuned semi-actuated control being used by the City of Tempe. The major contributions of the RHODES-ITMS Program can be categorized into the development and implementation (i) of new integrated hardware/software infrastructure that includes a new communication system, and (ii) of a traffic-adaptive signal control system. The infrastructure (i) integrates traffic-adaptive features within the 2070 Advanced Traffic Controllers, (ii) deploys, for the first time, a 2070 Controller within a TS2 cabinet, and (iii) implements a communication system for second-by-second decision making. The traffic-adaptive system has the following attributes and benefits: (i) it is second-by-second responsive, (ii) it has a hierarchical and distributed modular architecture that allows additional traffic control features, and (iii) it requires low maintenance of timing plans by traffic engineers. Last, but not least, the effort has extended the cutting edge in systems engineering methodology for the design of real-time decision-making systems and has expanded the workforce in traffic systems engineering by graduating several students through this research …