Exploring the distance decay in port hinterlands under port regionalization using truck GPS data

Ports are pivotal in the socioeconomic development of regions, countries, and cities as they serve as gateways for the transportation of goods between sea and land. Analyses of port hinterlands can enable port authorities and shippers to develop competitive strategies while assisting local authorities in identifying areas where inland transportation systems require improvement. In general, physical distance is a robust proxy for transportation costs. However, the role of distance in the context of port regionalization remains under debate, despite the spatial interaction model, with distance decay being commonly used to analyze the port–hinterland relationship. Doubt concerning the explanatory power of distance may act as an obstacle for port managers and local authorities in assessing the market share of ports, as well as in constructing planning agendas related to facility locations. This study examines the distance decay of port hinterlands using more than 0.18 billion points of heavy-duty truck GPS trajectory data from the Guangdong–Hong Kong–Macau Greater Bay Area. We develop an algorithm to compute heavy-duty truck flows and actual travel distance between the port and identified facility areas, and we apply the weighted least squares method to evaluate the explanatory power of six distance-decay models. Our findings reveal that the actual travel distance is a significant reduction factor in the port–hinterland relationship, while it follows the exponential model instead of a power function. This paper presents new evidence to reshape the role of distance in delimiting port hinterlands, providing port managers and local authorities with novel insights into the structure of port hinterlands in the context of port regionalization.