This paper examines the interaction between hinterland access conditions and port competition. Competition between ports is treated as competition between alternate intermodal transportation chains, while the hinterland access conditions are represented by both the corridor facilities and the inland roads. We find that when ports compete in quantities, an increase in corridor capacity by a region will increase its port’s output, reduce the rival port’s output, and increase its port’s profit. On the other hand, an increase in inland road capacity by a region may or may not increase its port’s output and profit, owing to various opposing effects. Essentially, while more road capacity reduces local congestion delays and moderates the negative impact of the port’s output expansion, it induces greater local commuter traffic and may moderate the effect by which a rise in cargo traffic reduces local commuter traffic, both of which reduces the port’s output and profit. Similarly, inland road pricing by a region may or may not increase its port’s output and profit. Finally, case examples for selected ports and regions are discussed.