Street-network Sprawl in Sulawesi Barat, Indonesia

What is Street-network sprawl?

Street-network Sprawl is a way to measure urban sprawl, worldwide, through the connectedness of the streets. Less sprawl means more connected, more walkable streets. Well-connected streets – like New York City’s grid – are more walkable and can be served by public transit.

The street network is permanent, and its connectivity affects the livability and environmental footprint of cities for decades and centuries to come. In places with more connected streets, residents drive less and walk more. A well-connected street network is associated with better outcomes for health, the environment, sustainable consumption, social integration, and equity.

We can quantify how connected street networks are with the Street Network Disconnectedness Index (SNDi).

SNDi -- our measure of street-network sprawl (disconnectedness)

The SNDi is a comprehensive measurement of “sprawl”. It captures:

A higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25.

More information on the sprawl index can be found in these research papers:

To see the state of street-network sprawl across the globe, visit the sprawlmap.

Sulawesi Barat: region in Indonesia

What exactly constitutes the spatial extent of the city? For these aggregations, we used the Global Human Settlement Layer Urban Center Database (GHS-UCDB) to define the boundaries of the city. These cities -- or urban centers -- cover areas that are densely populated and built-up, and so may extend beyond the spatial borders of these cities that we may be familiar with. The GHS area is shaded in blue.

View Sulawesi Barat, Indonesia on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Sulawesi Barat as of 2014, the overall level of street-network sprawl is 4.53, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.54, 5.36, 3.76 and 6.31. Disconnectivity in street construction in Sulawesi Barat follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 2001-2014.

Quantity of street network construction: The street network in Sulawesi Barat spans a total of 2963 kilometers. The period with the greatest volume of street construction was 1976-1990. These roads have an SNDi of 5.36, which is highly disconnected.

Effect on the aggregate network: New construction in each period adds to the total stock of streets, but does not change streets that have already been built. Therefore, it has a limited effect on the street network as a whole. The SNDis of the aggregate street network in the respective time periods are 3.54, 4.44, 4.3 and 4.53. Disconnectivity in Sulawesi Barat's street network follows a zig-zag trend. In 1975, the region was most disconnected; while it was most connected in 2001-2014.

The level of street-network sprawl in new development in Sulawesi Barat followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in Sulawesi Barat, we can consider three of its most populous cities: Mamuju, Takatidung and Polewali. Out of the three cities, Mamuju and Takatidung do not follow the same trend as the region. The level of street-network sprawl in new development in Mamuju followed a zig-zag trend with an overall increase. The level of street-network sprawl in new development in Takatidung was at its lowest in 1976-1990.

How do development practices in Sulawesi Barat fare in comparison to others in Indonesia? Most recently in 2001-2014, street construction in Sulawesi Barat was the 16th-most disconnected out of the 32 regions in Indonesia. Its position in the ranks since 1975 has risen; relative to other regions in Indonesia, street construction in Sulawesi Barat has become more disconnected. Sulawesi Barat ranked 30th in 1975, 11th in 1976-1990, 30th in 1991-2000 and 16th in 2001-2014.

As of 2014, the city with the most disconnected street network in Sulawesi Barat is Mamasa with an SNDi of 6.61, which is highly disconnected. Conversely, the most connected city is Pasangkayu with an SNDi of 1.32, which is relatively well-connected. See trends for these cities: Pasangkayu, Mamasa

The level of street-network sprawl in the aggregate network in Sulawesi Barat followed a zig-zag trend with an overall increase. To get a sense of how the aggregate street network has changed in Sulawesi Barat, we can consider three of its most populous cities: Mamuju, Takatidung and Polewali. Out of the three cities, Mamuju and Takatidung do not follow the same trend as the region. The level of street-network sprawl in the aggregate network in Mamuju rose steadily. The level of street-network sprawl in the aggregate network in Takatidung was at its lowest in 1976-1990.

To date, Sulawesi Barat is the 26th-most disconnected out of the 32 regions in Indonesia. Its position in the ranks since 1975 has risen; relative to other regions in Indonesia, the street network in Sulawesi Barat has become more disconnected. Sulawesi Barat ranked 30th in 1975, 22nd in 1976-1990, 27th in 1991-2000 and 26th in 2001-2014.