• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.4
• /
• pp.41-53
• /
• 2018

This study developed the optimization method to correct the measured traffic volume of the expressway that minimizes the measurement error and satisfies the traffic balancing with TCS. For this purpose, the model constructed in this study was compared and verified with the true traffic volume. Verification result of the model, it was found that the measurement error is reduced when the measured traffic volume is corrected for the traffic volume balance. As a result of applying it to 40 links of the Kyoungbu expressway, the measured traffic volume was corrected by -8.1%~9.6% and the measurement error was decreased as much as the corrected traffic volume. This research is meaningful in improving the accuracy of the measured traffic volume of the expressway, while the scale and role of the expressway are increasing.

• Journal of Korean Society of Transportation
• /
• v.28 no.6
• /
• pp.159-166
• /
• 2010

Trip distribution is to connect travel demand for each OD pair based on travel cost, trip production and attraction derived from trip generation step. In real world the travel cost is a function of travel demand, but existing models could not fully consider such functional relation between travel cost and demand, which leads to an equilibrium in trip distribution model. This paper proves the equilibrium trip distribution by using gravity model. In order to obtain such equilibrium this paper also presents a solution algorithm based on fixed point theorem. The algorithm will be tested with an example and confirmed the equilibrium solution of trip distribution.

• Journal of Korean Society of Transportation
• /
• v.20 no.6
• /
• pp.99-113
• /
• 2002

The multi-class traffic assignment problem is the most typical one of the multi-solution traffic assignment problems and, recently formulation of the models and the solution algorithm have been received a great deal of attention. The useful solution algorithm, however, has not been proposed while formulation of the multi-class traffic assignment could be performed by adopting the variational inequality problem or the fixed point problem. In this research, we developed a hybrid solution algorithm which combines GA algorithm, diagonal algorithm and clustering algorithm for the multi-class traffic assignment formulated as a variational inequality Problem. GA algorithm and clustering algorithm are introduced for the wide area and small cost. We also performed an experiment with toy network(2 link) and tested the characteristics of the suggested algorithm.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06d
• /
• pp.343-345
• /
• 2012

기존의 교통제어 시스템은 고정된 녹색 신호의 길이와 주기를 갖고 있다. 그에 따라 차선 간 차량 밀집도가 불균형한 경우 교통 처리량이 저하되고 응급상황이 발생할 경우 지정체가 유발된다. 본 논문에서는 VANET을 이용하여 교통량의 실시간 정보를 수집해 적응적으로 교통 신호를 제어하는 시스템을 제안한다. 차량의 수, 평균 신호대기 시간, 차선 간 균형, 응급상황 등을 고려하여 교통 신호를 가변적으로 제어 한다. 차량이 교차로에 진입하기 전 통신모듈을 갖고 있는 신호등에게 위치, 방향, 속도 정보 등을 송신하고 traffic control system에서 교통량을 분석하여 녹색 신호를 가변적으로 할당 한다. 실험결과 제안 기법이 교통 처리량, 평균 신호대기시간에서 기존 교통신호 제어 기법보다 높은 성능을 확일 할 수 있었다.

• 한국ITS학회:학술대회논문집
• /
• 2005.11a
• /
• pp.1-6
• /
• 2005

• Journal of Korean Society of Transportation
• /
• v.36 no.3
• /
• pp.195-202
• /
• 2018

Jobs-housing balance refers to the situations where the employment (work) and housing (house) opportunity are coincided in certain geographical area. This paper aims to examine the impact of jobs-housing balance to traffic safety. In pursuing the above, this paper particularly focuses on modeling the traffic accidents by metropolitan area. The main results are as follows. First, three generalized linear models which are all statistically significant are developed. Jobs-housing balance factors are judged to significantly influence on traffic accidents in all models. Second, among common variables, the housing supply rate is analyzed to impact to decreasing, and economically active population and commuting trip attraction are analyzed to impact to increasing. Hence, the alleviation of jobs-housing mismatch is evaluated to be important. Finally, the jobs-housing and business trip rates in Seoul metropolitan area, and the cross-commuting rate in Busan-Ulsan metropolitan area are judged to be essential to transportation safety policies

• Journal of Korean Society of Transportation
• /
• v.15 no.2
• /
• pp.51-66
• /
• 1997

실시간 변화하는 교통상황을 파악하고 교통혼잡을 완화시키려는 각종 교통정책들을 개발하고 평가하기 위하여 동적 통행배정모형에 대한 연구가 지속되고 있으며 상당한 성과 를 이루고 있다. 그러나 이론적인 어려움과 계산량과 과다로 기존의 모형들은 대부분 단순 가로망을 대상으로 적용되어 왔으며 대규모 가로망에 적용하는 데는 상당한 어려움을 겪고 있다. 본 연구의 목적은 실제 가로망에 쉽게 적용할 수 있는 휴리스틱 동적 통행배정모형을 개발하고 이를 해석할 수 있는 알고리즘을 개발하는 데 있다. 개발되는 모형은 변동부등식 (variational inequality)으로 구축되며 알고리즘은 휴리스틱 알고리즘(heuristic disagonalized algorithm)을 개발한다. 예제 가로망을 대상으로 개발된 모형을 평가하며 도출된 해가 Wrdrop의 균형해(equilibrium)임을 보인다.

• Journal of Korean Society of Transportation
• /
• v.18 no.2
• /
• pp.91-101
• /
• 2000

The optimal congestion charge in transportation economics corresponds to the solution to the welfare maximization Problem for users of a certain road link where congestion takes Place. This congestion charge is in nature the optimal Price of the transportation facility, which is derived by the Partial equilibrium analysis on that facility. Therefore it is not certain that this congestion charge can maximize the well-being of all the users of the total transportation network, since the analysis does not count the impact of the congestion charge on traffic volumes of other links. This study suggests an alternative approach to estimate the optimal congestion charge. The key difference of this study from Previous ones is to derive the solution through the general equilibrium analysis on a market where several transportation facilities as well as Private goods are available to consumers. This approach shows a set of solutions a little different from the Previous one, which are explained below. The optimal congestion charge is derived for two different cases. One is the situation of which the congestion charge is levied on every transportation facility In this case, the optimal solution of each facility should equate the marginal utility of every user to the marginal cost of the corresponding facility. This analysis result in general equilibrium coincides with the Previous analysis result in partial equilibrium. However this result cannot apply to another case of which the charge is imposed only on a certain transportation facility. In this case, the optimal charge on a certain transportation facility should be less than the optimal congestion charge of partial equilibrium analysis.

• Journal of Korean Society of Transportation
• /
• v.20 no.4
• /
• pp.95-107
• /
• 2002

Congestion and increasing returns to scale in the use of and in the provision of transportation facilities have been biggest challenges to policy makers. In order to counter these problems and thereby to promote economic efficiency, optimal congestion tax and marginal cost pricing are separately and strongly recommended for each case. In this paper, however, we show that they are valid only in Partial equilibrium context in which only the corresponding market is considered. We set up a formal general equilibrium model and prove that the recommended policies are not in general effective. We continue to give particular examples which show the invalidity of each policy and continue to show that in the same examples, there exist better but unconventional policies. Based on these findings we strongly suggest to employ quantify restricting policy measure or to find second-best pricing policies.

• Journal of Korean Society of Transportation
• /
• v.26 no.2
• /
• pp.147-156
• /
• 2008

It has been widely known that there are so many factors making travel demand errors in transportation forecasting steps. One of the reasons may stem from the level of aggregation of zone and network in analysis process. This paper investigates the effect of level of aggregation considering with number of zones in travel demand forecasting by expanding or reducing the zone and network gradually. Numerical results show that the aggregation could not make a significant impact on the travel demand, while disaggregation does. These results imply that a careful manipulation is required to add or to reduce zones and links in transportation planning process.