This study employs a percolation approach with road network data to examine the impact of road network expansion on urban agglomeration patterns in Java Island, Indonesia from 2009 to 2023. The percolation result demonstrates that the expansion of the...
This study employs a percolation approach with road network data to examine the impact of road network expansion on urban agglomeration patterns in Java Island, Indonesia from 2009 to 2023. The percolation result demonstrates that the expansion of the road network has reshaped the urban clusters of major cities in Java. Our model suggests that at the 1000-meter threshold, the development of urban clusters in Java becomes evident, aligning with population density data and built-up areas highlighting urban areas. Furthermore, the percolation analysis exposes Jakarta's substantial expansion beyond its administrative boundaries, encompassing Karawang and Purwakarta. This highlights the limitations of traditional methods relying on administrative boundaries, which can underestimate the true extent of urban agglomeration and hinder effective regional planning and growth control. This analysis also suggests the possibility of estimating future urban expansion that could lead to the merger of adjacent metropolitan areas. The integration of Jakarta-Bandung with more distant areas could create a larger urban cluster, establishing Jakarta and its surroundings as the largest mega-urban area in Java Island. The merger of other metropolitan areas is also evident in the case of Surabaya-Malang, where future urban expansion may exceed current administrative boundaries. These findings emphasize the need for integrated spatial policies that anticipate the impacts of road construction on urban sprawl and effectively manage growth across administrative boundaries.