• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.147-152
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• 2005

This study firstly developed a tool for evaluating performance requirements of automatic vehicle identification (AVI) techniques. A microscopic traffic simulator, Paramics, was employed to investigate the effects of AVI performances on the accuracy of estimating section travel times. Mote Carlo simulation approach was incorporated into Paramics to conduct systematic evaluations of identifying required AVI performances. The proposed method in this study can serve as a logical and necessary precursor to field implementation of a variety of AVI techniques toward achieving more reliable traffic information.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.1
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• pp.37-44
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• 2009

Density is the most important congestion indicator among the three fundamental flow variables, flow, speed and density. Measuring density in the field has two different ways, direct and indirect. Taking photos with wide views is one of direct ways, which is not widely used because of its cost and lacking of proper positions. Another direct density measuring method using two spot detectors has been introduced with the concept of instantaneous density, average density and measurement interval. The relationship between accuracy and measurement interval has been investigated using the simulation data produced by Paramics API function. Finally, density measurement algorithm has been suggested including exponential smoothing for device development.

• 한국ITS학회:학술대회논문집
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• 2010.05a
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• pp.126-131
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• 2010

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.125-134
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• 2009

Recently, as IT technology and the ubiquitous environment have diffused, the application of these techniques are being attempted in the field of traffic operations and management. Therefore, it is necessary to develop data collection systems and signal control strategies that are suitable in the ubiquitous environment and that will improve efficiency and safety of signalized intersections. The authors conducted a study on the Wireless Sensor Network (WSN) signal control strategy using a wireless communication network between individual vehicles and a signal-control system and full actuated signal control technique to propose a new signal control strategy in the ubiquitous environment. The WSN was defined to evaluate the algorithm used with PARAMICS API simulation. The simulation produced results that the WSN signal control is more effective than other signal control methods. The WSN signal control could reduce vehicle delay time to a maximum of 64% in comparison with other signal control methods in low and near saturation flow conditions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.2
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• pp.60-66
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• 2009

The acceleration noise is valuable index to monitor traffic stability. However, the previous study was performed for the acceleration noise of individual vehicle. The consideration of the acceleration noise for vehicle in the network has not been studied yet. This paper proposes a new macroscopic traffic flow monitoring method based on applying network acceleration noise.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.1-11
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• 2013

This research proposed integrated expressway traffic management strategy using ramp metering and toll mainline metering. This research suggested a traffic signal optimization model for integrated operation of ramp and mainline metering based on Demand-Capacity Model that is used to optimize allowable input volume for ramp metering in FREQ model. The objective function of this model is sectional throughput volume maximization, and this model can calculate optimal signal timings for mainline metering and ramp metering. This study conducted an effectiveness analysis of integrated metering strategy using PARAMICS and its API. It targeted Seoul's Outer Ring Expressway between Gimpo and Siheung toll gate. As a simulation result, integrated operation of mainline and ramp metering provided more smooth traffic flow, and throughput volume of mainline increased to 14% in congested section. In addition, a queue of 400 meter was formed at metering point of toll gate. This research checked that integrated traffic management strategy facilitates more efficient traffic operation of mainline and ramp from diffused traffic congestion.