Highway expansion and urban sprawl in the Jakarta Metropolitan Area

Transport development is widely recognized as one of the major drivers in shaping urban forms. While recent literature has documented the urban expansion effect of transport networks between cities, little is known about the effect within larger metropolitan areas. This study aims to find the causal relationships between highway expansion and two different aspects of urban development: urban expansion and urban sprawl in the Jakarta Metropolitan Area (JMA). To obtain the causal effect, we employ historic transport infrastructure as instrumental variables. Our results show that improvement in highway access increases urban sprawl within the JMA, particularly within 40–50 km radius from the city centre. The results also confirm the existence of highway-led urban expansion in several districts within the JMA over the last three decades. This paper adds a piece of enticing evidence that highway expansion leads to a sprawling development of urban areas even within a large metropolitan area.