In Seoul, congestion toll is collected at Namsan Tunnel 1 and 3 as a part of the transportation demand management (TDM) to ease the traffic congestion in downtown area since 1996. As the congestion toll policy has been implemented for 16 years, social interests grow on the re-evaluation of its effectiveness on the congestion mitigation and toll level.
During the initial period of the policy implementation in 1996, the traffic volume decreased to 25% for both tunnels, however traffic volume gradually increased and has now approached about 97% prior to the implementation. Accordingly, there is a need for a detailed review on such as improvements and effectiveness about road pricing policy in Namsan Tunnel 1 and 3.
In addition as the same amount of 2,000 won has been levied since the policy implementation in 1996, there are needs for determining the validity of the toll scheme, toll levels and range of vehicle exemption.
In this research, evaluation of the congestion pricing policy through quantitative analysis is conducted. Improvement for enhancing effectiveness of the congestion fee policy and the direction of future developments are derived.
The congestion pricing policy has influenced the traffic volume reduction. However, the degree of its effect on the current traffic flow has decreased as the price level has remained same for 16 years.
The congestion pricing policy has decreased the user cost when it was compared with the social cost while social welfare has increased. However the degrees of its effects are diminishing
External costs for Namsan tunnel 1 and 3 due to congestion are large, which indicates that it is necessary to adjust the level of the current congestion fee rates. Variable pricing is necessary to enforce the Namsan Tunnel 1, and the bi-directional congestion toll system is sought to be a reasonable.
Results on the analysis of the adequacy of the vehicle exemption shows that taxi, green car, one week day-off car and small-sized car should be recommended. To attract the use of current exempted cars, it is desirable to maintain the current exemption system for the time being.
It is sought to be that the expansion of congestion toll range should include the Hangang-ro road as the traffic congestion cost is much larger than other bypass roads of Namsan tunnels. Finally, the effect of line-based congestion pricing system is limited to decrease volume, so it is necessary to switch to the area based congestion tolling.