- Author:
- Didier M. Valdes Diaz,
- Supervisor:
- Hani S. Mahmassani
Traffic congestion is a major problem in freeway corridors in many urban areas. Efforts to alleviate congestion include the use of advanced technologies, collectively known as Intelligent Transportation Systems (ITS). These include Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS), which provide enabling technologies and better traffic management opportunities. However, to obtain the expected benefits, there is a need for procedures to integrate and coordinate the operation of complex freeway corridor networks.
The main focus of this research is to develop and evaluate an integrated framework that combines traffic control elements with information supply aimed at route-guidance. Traffic control strategies are designed to manage the traffic on the freeway and the street network. Information strategies are designed to guide vehicles through the corridor network so as to improve the entire system performance. Information includes pre-trip and en-route information considering prevailing or predicted conditions.
The integrated operational framework provides different levels of coordination; it is evaluated using a simulation-assignment approach to capture the system dynamics under non-recurrent congestion caused by an incident located on the freeway. Integrated strategies are applied to manage traffic and reduce the negative effects caused by the incident. The solution methodology considers two main strategies: a reactive strategy to be applied immediately when a surge situation is detected, and an anticipatory strategy that provides information to users before they reach the incident and sets the control parameters in anticipation of the arrival of vehicles to each controlled facility.
A new procedure is developed in this thesis to supply information to system users by using optimal time-dependent Variable Message Signs (VMS) diversion rates. In addition, a signal control strategy called path-based coordination is developed and applied. This strategy consists of identifying critically used paths (including turning movements), and providing progressive movement of vehicles along these paths through signal synchronization.
A number of simulation-based experiments are conducted to evaluate the integrated control framework and associated strategies, and assess the benefits and improvements in terms of reduced travel time and saved delay to motorists by applying integrated traffic control and information strategies.
Recommendations
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