After opening of the Inner-Circular Freeway in Seoul, the efficient management of the urban freeway system has been a critical issue. Safety and congestion problems are the main concerns. Heavy congestion takes place almost every day owing to ramp queues caused by poor coordination of exit ramps. Every week several people are killed in accidents because of the narrow shoulders and inferior geometric design of the freeway. Urban FTMS (Freeway Traffic Management Systems) are regarded as one possible solution for the severe traffic congestion and safety-threatening environment. Vehicle Enforcement Systems (VES) and Ramp Metering Systems (RMS) are considered as main aid to ease the pain. The first phase of urban FTMS project will open this fall for the Inner-Circular Freeway. The system-wide and locally isolated ramp metering has been designed and tested in the freeway for the first phase deployment. Presently, the second phase of FTMS project is underway. The Northern-Arterial Freeway and North-Riverside Freeway is the domain of the project. The purpose of this paper is to evaluate the RMS for the second phase of the Seoul Urban Freeway FTMS. In this paper, the authors made the strategic plan for the RMS. Then, the ramp control scheme is designed and suggested. Finally, the authors made three incident scenarios for the evaluation and performed simulation: 1) Normal Condition, 2) 5 minutes one-lane block condition, 3) 10 min one-lane block condition. The effect of RMS is presented in terms of average link speed. Finally, policy issues concerning RMS are discussed.
Samenvatting