Urban road pricing and sustainable transportation systems: the Thessaloniki central area case

Abstract

Urban road pricing involves direct charging of drivers for the use of the road network, usually during peak periods. The main objectives for the introduction of a road pricing scheme, in a congested city network, include reduction of delays, environmental improvement and revenue increase. These objectives are closely associated with the concepts of sustainable mobility in urban areas with respect to social equity, economic effi ciency and environmental responsibility. This paper attempts to estimate the potential interrelation between urban road pricing and sustainable mobility management policy by modelling the impacts (traffi c network operation, environmental indices and revenue) of a hypothetic implementation of cordon tolls in the city centre of Thessaloniki (situated in northern Greece), which faces severe traffi c and environmental problems. The evaluation was carried out using the SATURN traffi c simulation model, which was developed at the Institute for Transport Studies, University of Leeds, UK. SATURN is a well-known transport analysis model which is widely used. In order to assess the impacts of traffi c scenarios, the software runs a simulation-assignment procedure simultaneously using commonly accepted algorithms that originate from transport theory such as all-or-nothing assignment, Wardorp’s principles. The road network used in SATURN for the purposes of this research consists of 813 nodes and 293 zones. Furthermore, an analysis was carried out regarding the contribution of the extracted model indicators to the establishment of an overall strategy concerning sustainable transportation and mobility in Thessaloniki’s central area. Various scenarios were examined depending on the year of the analysis and the alternative transport mode in use. These scenarios were compared with different road charging scenarios. Parameters such as traffi c volumes, speed, vehicle emissions were estimated. A comparative analysis of these values in conjunction with the defi nition of sustainable mobility and development in general was performed, concluding that innovative measures can reassign the trip patterns in urban areas, thereby improving the transport system operation in terms of sustainability. Undoubtedly, the use of powerful assessment tools such as SATURN for the evaluation of the impacts of various Transportation Demand Management measures like road charging will provide valuable assistance to policy makers and the transportation planners involved in the specifi c process.