• International Journal of Highway Engineering
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• v.18 no.2
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• pp.91-101
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• 2016

PURPOSES : The aim of this study was to compare the performance of the QUEENSOD method and the gravity model in estimating Origin-Destination (O/D) tables for a large-sized microscopic traffic simulation network. METHODS : In this study, an expressway network was simulated using the microscopic traffic simulation model, VISSIM. The gravity model and QUEENSOD method were used to estimate the O/D pairs between internal and between external zones. RESULTS: After obtaining estimations of the O/D table by using both the gravity model and the QUEENSOD method, the value of the root mean square error (RMSE) for O/D pairs between internal zones were compared. For the gravity model and the QUEENSOD method, the RMSE obtained were 386.0 and 241.2, respectively. The O/D tables estimated using both methods were then entered into the VISSIM networks and calibrated with measured travel time. The resulting estimated travel times were then compared. For the gravity model and the QUEENSOD method, the estimated travel times showed 1.16% and 0.45% deviation from the surveyed travel time, respectively. CONCLUSIONS : In building a large-sized microscopic traffic simulation network, an O/D matrix is essential in order to produce reliable analysis results. When link counts from diverse ITS facilities are available, the QUEENSOD method outperforms the gravity model.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.31-37
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• 2008

Traffic flow which is prescribed under previous traffic effect/access act is analyzed by traffic volume, V/C, mean speed on road and LOS on the intersection. These indexes based on analytical method can not consider stochastic characteristics of traffic flow. Moreover it is hard to analyze traffic flow visually in whole traffic effect area because only individual road and intersections are targeted. In this study, it is devised to show traffic flow analysis method within traffic effect area visually applying microscopic-simulation by car-following theory, and then based on this, effect analyze ways are studied according to space range plan, improvement measure establishment and etc. To execute this study, effect area is set up using V/C, and the change of traffic current around development area is analyzed using microscopic-simulation program.

• Journal of Korean Society of Transportation
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• v.14 no.1
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• pp.101-116
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• 1996

Increased attention has been paid in recent years to the need of traffic management for alleviating urban traffic congestion. This paper presents a discrete event modeling and simulation framework for analyzing the traffic flow. Traffic simulation models can be classified as being either microscopic and macroscopic models. The discrete event modeling and simulation technique can be basically employed to describe the macroscopic traffic simulation model. To do this, we have employed the System Entity Structure/Model Base (SES/MB) framework which integrates the dynamic-based formalism of simulation with the symbolic formalism of AI. The SES/MB framework supports to hierarchical, modular discrete event modeling and simulation environment. We also adopt the Symbolic DEVS (Discrete Event System Specification) to developed the automated analysis methodology for generating optimal signal light policy. Several simulation tests will demonstrates the techniques.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.5
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• pp.15-26
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• 2012

Government agencies including the national police agency have executed diverse efforts including continuous improvements of traffic facilities and operation methods, education, enforcements in order to improve traffic operation systems; nevertheless there have been continuous criticisms on irrationality in traffic signal and road facility operation. One of the reasons may be the lack of systematic preliminary evaluations on various alternatives. However, there was no appropriate tool to evaluate the mobility and safety of thus alternatives in a systematic way. Therefore, this study proposes the systematic use of microscopic traffic simulation models as a comprehensive evaluation tool. In addition, this study verified the potential of using a microscopic traffic simulation model using the case of operating an overlap phase on a shared-left-turn lane through a systematic way where the evaluation was conducted through data collection, building networks, calibrating microscopic simulation models, producing performance measures, evaluating mobility and safety, and so on. As a result, the operation of overlap phase on a shared-left-turn lane showed no big difference from other operation scenarios such as leading left-turn on exclusive left turn lane in terms of mobility. However the operation of overlap phase on a shared-left-turn lane decreased safety by increasing potential conflicts.

• Spatial Information Research
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• v.23 no.4
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• pp.79-89
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• 2015

This study aims to design and implement a traffic model that can simulate the traffic behavior on the microscopic level by using the GIS. In the design of the model, the vehicle in the simulation environment recognizes the GIS road centerline data as road network data reflecting number of lanes, speed limit and so on. In addition, the behavior model was designed by dividing functions into the environmental perception model, time headway distribution model, car following model, and lane changing model. The implemented model was applied to Jahamun-road of Jongno-gu district to verify the accuracy of the model. As a result, the simulation results on the Jahamun-road had no great error compared with the actual observation data. In the aspect of usability of model, it is judged that this model will be able to effectively contribute to analysis of amount of carbon emission by traffic, evaluation of traffic flow, plans for location of urban infrastructure and so on.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.1-14
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• 2011

The surrogate safety assessment model which was developed based on the conflict theory by FHWA in the US is software to analyze traffic conflicts using the individual vehicle trajectory data from a microscopic traffic simulation model. This study aims at assessing the safety of different signal control strategies, including pre-time and actuated signal control, using the SSAM. To this end, this study effort has developed a microscopic traffic simulation model using VISSIM through a field study, and then produced the surrogate measures, including TTC, PET, DR, MaxS and DeltaS, and the numbers of conflicts, including rear-end, right angle and lane-changing conflicts. The assessment results indicated that the actuated signal control may produce more conflicts in terms of rear-end conflicts. The use of SSAM in the safety assessments for diverse traffic alternatives in a safe and fast way may contribute to the improvement of safety in the roadway transportation.

• Journal of Korean Society of Transportation
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• v.13 no.1
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• pp.185-203
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• 1995

The purpose of this paper is to develop a microscopic traffic simulation model which is able to both analyze and the evaluate signlaized urban network and to verify its usefulness in comparison with the other model which has alfeady been released. This simulation model adopts the General Motor's 5th model for car-following and introduces an unique lanechanging rule using acceptable gap. It analyzes single and dual-ring signal phases and generates detector information . So it could be applied to dynamic route guidance systems as wel as real time signal control systems. The results derived from Netsim and the observed data from the real network have been used to test the validit of the proposed model. The result of the test has shown that there are no significant differences between the NETSIM model and the proposed model in estimating travel speed and stopped delay. In optimum offset estimatin , it has shown the same results with NETSIM. the measure of effectiveness , however, derived from this model is slightly better than that of the real network situation. This may be due to the fact that the proposed model does not take into account side frictions from interferences and obstacles.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.143-160
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• 2001

Micro-simulation models have been recognized as an efficient assessment tool in developing traffic signal control technologies. In this paper a prototype of a microscopic simulation model which can be applied to evaluate the performance of traffic-adaptive signal control strategies was developed. In the simulation process, space-based arrays were appled to estimate parameters of car following and lane changing models. Two levels of link types, a micro-type and macro-type links, were also embodied in the simulation process. The proposed model was tested on a test network consists of 9 intersections. The performance of the proposed model was evaluated in link by link comparisons with the results of NETSIM. The results show that the proposed model could appropriately simulate traffic flows of the test network. The model also produces traffic adaptive signal timings, cycle lengths and green times for turning movements, based on the detector data. It implies that the optimization process of the model produces reasonable signal timings for the test network on the cycle basis.

• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.167-168
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• 2014

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.789-792
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• 1993

We have proposed a fuzzy model for behavior of vehicles in the road traffic simulation system with microscopic model for analyzing traffic jam in the broad areas. It can exactly simulate each vehicle's behavior. We propose a new hardware processor to simulate fuzzy decision-making mechanism for its model. This paper describes the functions, performance and structure of the hardware processor.