Identification of Urban Hinterland Based on Traffic Accessibility: A Case Study of Guangdong-Hong Kong-Macao Greater Bay Area

To effectively define the spatial scope of urban agglomeration considering traffic conditions and urban economic links so as to assist the transportation planning and spatial integrative development of the Guangdong-Hong Kong-Macao Greater Bay Area, firstly, the spatial pattern of raster grid highway traffic accessibility, road network density and economic connection intensity for the Guangdong-Hong Kong-Macao Greater Bay area were calculated and analyzed based on geographic information system (GIS) spatial analysis technology and modified gravity model. Then, different scales of urban hinterland were extracted and divided basing on highway traffic accessibility and urban connection degree. The research shows that the urban traffic accessibility of Guangdong-Hong Kong-Macao Greater Bay Area increases in a circle of " core-periphery " with Guangzhou-Foshan, Shenzhen-Guanzhou and other central cities as the center, while the traffic accessibility in counties presents a distribution pattern of " high in the middle and low at both ends". The overall traffic accessibility of Guangdong-Hong Kong-Macao Greater Bay A-rea is at a high level, but all the cities in the Greater Bay Area have not yet achieved 1h access. Under the special development background of "one country, two systems and three customs zones", the traffic linkages and coordination mechanisms between cities and within cities in the Bay Area are still relatively weak, and the traffic bottleneck problems in the inter-provincial and inter-city administrative boundaries are still prominent. The spatial network trend of economic connection intensity in the research area is significant. The leading cities such as Shenzhen, Hong Kong, Guangzhou, Foshan and Dongguan have obvious radiation effects, while the low value areas are distributed in the marginal areas with poor traffic accessibility. The urban hinterland area considering traffic conditions and economic scale in the Guangdong-Hong Kong-Macao Greater Bay Area does not match the corresponding administrative area. The urban hinterland of the two-wings in the Greater Bay Area is gradually "nibbed" by the central core cities. It is suggested to promote the internal space linkages between the central core cities of the Guangdong-Hong Kong-Macao Greater Bay Area urban and to promote the population flow and traffic flow. Thus can give full play to the intermediary role of the secondary center in cross-regional cooperation, and ultimately achieve the regional traffic planning and management of the super-large area without administrative constraints and realize the sustainable and balanced development of the Greater Bay Area. © 2021, Editorial Department, Journal of South China University of Technology. All right reserved.