The unbalanced traffic flow in the three Road Harbour Crossings (RHCs) connecting Hong Kong Island and Kowloon Peninsula is a very serious transportation problem in Hong Kong. A very important question about the toll structures, i.e. how to set the toll for different vehicle types, is raised during the study of the utilization of the three RHCs. Traditionally, the toll structure is determined according to the cost of maintenance contribution. A per axle pricing system is being adopted in many examples in the world. In transportation economics, the toll charge is studied extensively. However, no study has been done on the methodology to determine the optimum toll structure. This dissertation suggests a new methodology to determine the optimum toll structure. It suggests each type of vehicles should pay the same full cost, i.e. monetary cost plus the time cost. Value of time and occupancy are emphasized during the consideration of the time cost of each type of vehicles. As the time cost of the vehicles varies with the congestion level, the optimum toll structure depends on the congestion level of the road. This dissertation investigates the factors affecting the demand and supply of the RHCs. They are used to predict the total travel time and social welfare under different toll structures. It shows the suggested methodology can maximize the social welfare generated from the tunnel. Optimum toll for CHT is found using the suggested methodology. Optimum toll for EHC and WHC after their franchises expire in 2016 and 2023 are also found. Recommendations are also made in this dissertation to reduce the possible objections from the general public due to the toll adjustments. / published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

published_or_final_version / Transport Studies / Master / Master of Arts