• 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.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.520-530
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• 2015

This paper formulates the methodologies to estimate optimal congestion tolls from long-run and short-run perspectives and applies them to the highways of Seoul. An optimal long-run congestion toll is estimated with an optimal volume-capacity-ratio to minimize the total costs which consist of two components: road construction and maintenance costs and traveler costs. By contrast, an optimal short-run congestion toll is estimated with a supply-demand equilibrium which is determined by using a speed-flow function and a disaggregate modal choice model. The results of a long-run analysis for the Seobu urban expressway suggest the optimal volume-capacity-ratio of 1.35 and the optimal congestion toll of 503 Won per automobile kilometer. By contrast, those of a short-run analysis for the Mia-ro urban arterial suggest 1.31 and 420 Won, respectively. Although our results are to some degree dependent on the interest rate and time value assumed, one basic conclusion holds up: the congestions toll tested could generate substantial gains in social welfare if applied to Seoul.

• Journal of Korean Society of Transportation
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• v.32 no.4
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• pp.357-368
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• 2014

So far, land use-transportation models have been used exclusively for numerical analysis. A recent theoretical endeavor now enables us to derive the first-order derivative of the model's welfare function with respect to policy variables. I extend this methodology into the institutional setting where toll revenues are recycled through labor income tax. In this setting, the first-order derivative is composed of (1) the increase in welfare due to reduced congestion, and (2) the decrease in welfare due to interaction with the existing labor income tax. This result coincides with existing theory in the non-spatial model.

• Journal of the Korean Operations Research and Management Science Society
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• v.3 no.1
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• pp.31-46
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• 1978

Consider a time interval during which the demand for trips is fixed (e.g. the rush hour period). The traveller has a choice between various public modes, whose travel times and fares are fixed, and the automobile mode, for which travel time and cost depend on the volume of traffic flow on those roads, which are subject to congestion. We consider the equilibrium in terms of a representative travellerm, who choses for any trip the mode and route with the least combined money and time cost. When several (parallel) model or routes are chosen, then the combined cost of money and time must be equal among these. Our problem is first, to find the optimal flows of cars and of public mode carriers on the various links of their networks and second the optimal fares for trips by the variousmodes. The object is to minimize the total operating costs of the carriers and car plus the total time costs to travellers. The optimal fares are related to, but not identical with the dual variables of the underlying Nonlinear Program. They are equal to these dual variables only in the case, when congestion tolls on trips or on the use of specific roads are collected from automobile users. When such tolls are not collected, they must be passed on as subsidies to travellers using competing modes. The optimal fares of public modes are then reduced by the amounts of these subsidies. Note that subsidies are not a flat payment to public carriers, but are calculated on the basis of tickets sold. Fares and subsidies depend in general on tile period considered. They will be higher during periods of higher demand. When the assumption of fixed trip demand is relaxed, this tare system is no longer best, but only second best since too much traffic will, in general, be generated. The Free Rider Theorem states the following : Suppose road tolls can be charged, so that a best pricing system for public modes is posssible. Then there may exist free rides on some routes and modes, but never on a complete round trip.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.101-109
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• 2007

Two variations of toll roads exist: mainline toll plazas and entry/exit tolls. On a mainline toll system(open toll scheme), all vehicles stop at various locations along the highway to pay a toll. While this may save money from the lack of need to construct tolls at every exit, it can cause lots of traffic congestion, and drivers could evade tolls by going around them. With entry/exit tolls, vehicles collect a ticket when entering the highway, which displays the fares it will pay when it exits, increasing in cost for distance travelled. Upon exit, the driver will pay the amount listed for the given exit. The pressures on the Seoul ring roadway network have been changing over time. In the past, the emphasis was on mobility and maintenance of the road network to provide an efficient transportation network, but recently, road use has outstripped the network's ability to extend and expand the road network and hence the policy emphasis has moved towards reducing free riders rather than mitigating its effects. In addition to this pressure is an incidental pressure, which argues that provision of free ride segments generates further traffic in isolation of other factors. This paper is examining policies to reduce the burden of traffic congestion in Seoul ring roadway which is used open toll scheme for decades. One key mechanism to achieve this policy aim is automatic charging mechanism on freeway, but if a nation-wide electronic toll collection is to be implemented successfully, there are a number of prerequisites which must be place.

• Journal of Korean Society of Transportation
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• v.14 no.1
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• pp.7-27
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• 1996

It is very costly to construct transportation facilities such as roads, bridges, tunnels, and public parking lots mainly because land price is very high in metropolis like Seoul. Private car oweners use these facilities more extensively than public transportation users. However, the government does not impose proper charges for using these facilities. Such improper charge causes traffic congestion and then decreases social welfare in efficiency and equity. To solve problem, many traffic demand management policies are used. Traffic management policies which are currently used or under consideration by the City Government of Seoul include the imposition of road tolls, increase of parking fees in public parking lots, increase of gasoline taxes, expanded implementation of bus only lanes, and shippujae, which requires one(1) non-driving day for 10 calendar days. This study examined the impacts of such policies on the different income classes using simulation analysis. We found that the impacts of market-oriented policies such as the imposition of road tolls and the increase of gasoline taxes is regressive. Also, we found that while the low and middle income private car users have incentive have incentive for public transportation use, the high income private car users have no incentive for public transportation use in many cases.

• 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.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.77-89
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• 2009

With an increasing number of cars in Korea, the government is constantly providing roads and their related facilities. However the fundamental problems of cities like the structure of cities and the environment of roads make the traffic congestion of downtowns. To solve this problem the construction of toll roads such as tunnels and bridges is increasing but use rates of drivers is low. With more tolls required, less persons will use the roads. Thus this study is to consider offering discounted charges when using the two or more toll roads together. This study analyzes the impact that discounted charges would bring to the demand. In the meantime we looks into what the proper range should be for the discount. The results of this study are expected to be used as basis for the introduction of a discount system in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.97-107
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• 2004

As one of the most serious urban problems, routine city traffic congestion causes not only unpleasantness but also damage with increases of road tolls. Recently, many TDM plans are being improved along with plans to more effectively utilize established facilities and maximize the effect. To achieve the purpose of Intelligent Transport Systems(ITS). Recently, the core of ITS is Advanced Traveler information Systems (ATIS.) that are activity researched. A development of various muti-media system is very important of road guideline. First of all a business processing for offering travel information and give a consideration to the United states of various muti-media systems.

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.31-40
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• 2009

Some road charges toll to finance the cost or to manage traffic congestion. With a growth of PPI projects, toll roads would be increase continuously. Tolls have a considerable influence on user's route choice, and sometimes can affect to the departure time and even to mode choice. For modelling toll roads, user's WTP or VOT has an important role and it is general that VOT is equivalent to the wages of workers. The current way of modelling technique yields various toll price elasticity from low to high. When there exist few alternative routes, unrealistic result that all traffic assigned to some shortest path may occur. The toll price elasticity can be influenced by alternative route and congestion level, but some result shows nearly unrealistic patterns. The model to forecast more realistic toll road demand is very essential for estimating toll revenue, choice of optimal toll level & collecting location and establishing toll charge strategy. This paper reviewed some literatures about toll road modelling and tested case study about the assignment technique with different VOT. The case study shows that using different VOT yields more realistic result than the use of single VOT.