Abstract: At present, important advances in transportation costs studies have been achieved at sector and enterprise levels. However, at the regional level, relevant studies focused primarily on the impacts of transportation costs. Based on the regional perspectives and macro-scales, this paper attempts to build a theoretical framework on the regional integrated transportation costs, which consists of its concept, the main influencing factors, the measurement model, the mechanism of pattern formation and changes, and the spatial-temporal evolution rules. For a particular geographic unit, the regional integrated transportation cost is a general measurement of the resistance of passenger and cargo flows, which is greatly influenced by the integrated transportation accessibility, the passenger and freight traffic scale, and the external costs of transportation, with the integrated transportation accessibility serving as a fundamental role. On this basis, the integrated transportation costs index is built to reflect the difference among node costs. The formation and evolution of the pattern of regional integrated transportation costs is the comprehensive result of the distribution pattern of transportation infrastructure, the stage of economic and social development, and the relevant policies. In general, spatial pattern evolution of integrated transportation costs follows a four-stage evolution model: Primary Divergence - Convergence - High Convergence - Divergence. The integrated transportation costs decrease gradually over the time, and its spatial distribution evolves from the initial equilibrium to non-equilibrium, and eventually to the high-level equilibrium.

Key words: regional integrated transportation costs, measurement model, pattern, mechanism, spatial-temporal evolution