In November 1996, the City of Seoul imposed a fee on motorists driving through two tunnel corridors, Namsan 1^st and Namsan 3^rd tunnel, to mitigate traffic congestion. This research examines the effectiveness of pricing scheme and analyzes the toll elasticity at the two tunnels over the 12 years of operation. The traffic volume decreased 14% during the first two years and maintained almost constant after that. By implementing congestion pricing, travel speed increased from 22 km/h to 32 km/h for two years even though overall speed along other monitored roadways in Seoul remained unchanged. Also, the number of passenger cars has been considerably reduced up to 34% during the same period with increases in buses (62%) and taxis (211%). The toll elasticities estimated from empirical data in Seoul are -1.47 on Namsan 1^st tunnel which is larger than those found in other countries, while -0.38 on Namsan 3^rd tunnel.