• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.123-138
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• 2009

This study examined the first- and second-best pricing by stable dynamics in congested transportation networks. Stable dynamics, suggested by Nesterov and de Palma (2003), is a new model which describes and provides a stable state of congestion in urban transportation networks. The first-best pricing in user equilibrium models introduces user-equilibrium in the system-equilibrium by tolling the difference between the marginal social cost and the marginal private cost on each link. Nevertheless, the second-best pricing, which levies the toll on some, but not all, links, is relevant from the practical point of view. In comparison with the user equilibrium model, the stable dynamic model provides a solution equivalent to system-equilibrium if it is focused on link flows. Therefore the toll interval on each link, which keeps up the system-equilibrium, is more meaningful than the first-best pricing. In addition, the second-best pricing in stable dynamic models is the same as the first-best pricing since the toll interval is separately given by each link. As an effect of congestion pricing in stable dynamic models, we can remove the inefficiency of the network with inefficient Braess links by levying a toll on the Braess link. We present a numerical example applied to the network with 6 nodes and 9 links, including 2 Braess links.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.145-155
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• 2009

This paper compares the relative performances of area and cordon tolls as opposed to the first-best congestion tolls with respect to alleviation of traffic congestion and social welfare. The comparison is done in the monocentric city where all the jobs are located at the city center. The study shows that the size of charging zones is similar in the two second-bests, but that the optimal toll level is higher in area pricing than in cordon pricing. Area pricing schemes turn out to perform better than cordon pricing schemes as measured by average speeds and daily average travel time. Accordingly, the former is shown to increase the social welfare more than the latter. In the case of the cordon tolls, the residents at the charging zones are exempted from the tolls. In this way, cordon tolls invite people into the most congested areas over the optimal level while partially negating the whole spirit of the congestion tolls.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.159-169
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• 2008

The aim of this paper is to research the changes of social welfare by internalizing external cost, especially the maintenance cost. Main target of this paper is the Cheonan$\sim$Nonsan Line, where private capital highway, national highway and local road are competing against each other. Considering the realistic difficulties in applying the First Best pricing, this paper applied the Second Best pricing, applying the maintenance cost, in lieu of the already mentioned. The demand functions of the toll roads were built through regression analysis. By reflecting the maintenance cost to the toll fee, It was able to confirm the variation of social welfare deriving from the traffic assign change but also the aspects of toll revenue at the same time. Result of applying the Second Best pricing shows merely a small change in social welfare. However, in the aspect of finance, it is analyzed that there will be about 13 billion won worth of financial effectiveness which will contribute to the reduction of the national financial support.

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.71-80
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• 2005

With rapid development Telematics industry, the concern of dynamic road pricing system is increasing. In this study, the change of traffic flows according to traffic information and variation of congestion road prices related to the dynamic road pricing was analyzed. In this study, three facts were unfolded. First, high delay penalty and low delay penalty drivers are shown different reaction for the different congestion road prices. Second, the higher congestion road prices the more drivers convert their route from toll road to non toll road. Third, high penalty drivers are converting to toll road than low delay penalty drivers under same congestion road prices. This study has reached the conclusion that dynamic congestion pricing has a high possibility for traffic management.

• Journal of Korean Society of Transportation
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• v.25 no.1 s.94
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• pp.7-21
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• 2007

The purpose of this study is to examine the transportation, equity and efficiency impacts of cordon pricing schemes in the Seoul Capital Region of Korea. Autos would be required to pay a toll of 2.000 Won each time they enter cordons around the CBD or the subcenters during morning peak periods. The imposition of the toll would produce a substantial decrease in traffic volumes within the cordons as well as throughout the Capital Region. The lower the income level of commuters is, the more the share of auto decreases and that of transit increases. For equity impacts, the welfare of commuters would increase or decrease according to the cordon pricing schemes but would produce progressive impacts irrespective of the schemes. However, the commuters who have the highest value of time would experience welfare gains and it would result in regressive impacts. The schemes would result in a substantial net social welfare gain for the efficiency impacts. When the toll is charged at the CBD cordon only, the net social welfare would increase more.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.675-685
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• 2014

This paper develops a differentiated pricing strategy over each segment of expressways based on the second-best pricing method for reducing congestion. To this end, a bi-level problem is proposed, in which the upper level of the model is formulated to determine toll level of each segment for minimizing traffic congestion, whereas the lower level of the model is formulated as a variable demand assignment problem. The sensitivity analysis based algorithm is took placed to find optimal solutions of upper level model. An application of the proposed model uses the modified Sioux-Falls network. The results show that the segment-based differentiated pricing strategy performs better than the existing uniform pricing strategy in reducing traffic congestion. This study can be applied as a demand management method to relieve disutility of excessively congested segments of expressways.

• Proceedings of the KOR-KST Conference
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• 2007.11a
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• pp.104-113
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• 2007

• 한국ITS학회:학술대회논문집
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• v.2006 no.10
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• pp.62-70
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• 2006

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.31-41
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• 2006

The main purpose of this paper is to develop the practical method to estimate the congestion price in odor to overcome the difficulty of traditional microeconomics approach for demand and cost function concepts. In this paper, we estimate the theoretical congestion toll which reflecting the real traffic conditions such as a speed-density functions using a traffic engineering methods We calculates the optimal congestion toll based on the real traffic conditions assuming that the electronic road pricing (ERP) systems ave installed for the study road. After evaluating the various speed-density relationship methods. we found that the Drake model is best suited for the Gangbyeon Expressway Using the Drake model, the optimal congestion toll will be 94 to 3,255 Won for the traffic speed between 44km/h to 68 km/h based on wage rate method and 107 to 6,381 Won for the marginal substitution method for the Gangbyeon Expressway in city of Seoul, Korea.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.139-149
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• 2004

As the expansion of road capacity has become impractical in many urban areas, congestion pricing has been widely considered as an effective method to reduce urban traffic congestion in recent years. The principal reason is that the congestion pricing may lead the user equilibrium (UE) flow pattern to system optimum (SO) pattern in road network. In the context of network equilibrium, the link tolls according to the marginal cost pricing principle can user an UE flow to a SO pattern. Thus, the pricing method offers an efficient tool for moving toward system optimal traffic conditions on the network. This paper proposes a continuous network design program (CNDP) in network equilibrium condition, in order to find optimal congestion toll for maximizing net economic benefit (NEB). The model could be formulated as a bi-level program with continuous variable(congestion toll) such that the upper level problem is for maximizing the NEB in elastic demand, while the lower level is for describing route choice of road users. The bi-level CNDP is intrinsically nonlinear, non-convex, and hence it might be difficult to solve. So, we suggest a heuristic solution algorithm, which adopt derivative information of link flow with respect to design parameter, or congestion toll. Two example networks are used for test of the model proposed in the paper.