Street-network Sprawl in Tambakrejo, 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.

Tambakrejo: city in Jawa Timur, 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 Tambakrejo, Indonesia on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Tambakrejo as of 2014, the overall level of street-network sprawl is 2.44, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, 1.65, 1.94 and 3.23. Data was not available in 1975.

Quantity of street network construction: The street network in Tambakrejo spans a total of 68 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of nan, 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 nan, 1.65, 1.78 and 2.44. Data was not available in 1975.

Tambakrejo and Jawa Timur do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Jawa Timur rose steadily.

How do development practices in Tambakrejo fare in comparison to others in Jawa Timur? Most recently in 2001-2014, street construction in Tambakrejo was the 33rd-most disconnected out of the 52 cities in Jawa Timur. Its position in the ranks since 1975 has risen; relative to other cities in Jawa Timur, street construction in Tambakrejo has become more disconnected. Tambakrejo ranked 37th in 1976-1990, 37th in 1991-2000 and 33rd in 2001-2014. There was no ranking in 1975 due to unavailable data.

Tambakrejo and Indonesia do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Indonesia followed a zig-zag trend with an overall increase.

How do development practices in Tambakrejo fare in comparison to others in Indonesia? Most recently in 2001-2014, street construction in Tambakrejo was the 203rd-most disconnected out of the 363 cities in Indonesia. Its position in the ranks since 1975 has fallen; relative to other cities in Indonesia, street construction in Tambakrejo has become more connected. Tambakrejo ranked 193rd in 1976-1990, 227th in 1991-2000 and 203rd in 2001-2014. There was no ranking in 1975 due to unavailable data.

Tambakrejo and Jawa Timur do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Jawa Timur rose steadily.

To date, Tambakrejo is the 36th-most disconnected out of the 52 cities in Jawa Timur. Its position in the ranks since 1975 has risen; relative to other cities in Jawa Timur, the street network in Tambakrejo has become more disconnected. Tambakrejo ranked 40th in 1976-1990, 39th in 1991-2000 and 36th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Tambakrejo and Indonesia do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Indonesia was at its lowest in 1976-1990.

To date, Tambakrejo is the 265th-most disconnected out of the 363 cities in Indonesia. Its position in the ranks since 1975 has risen; relative to other cities in Indonesia, the street network in Tambakrejo has become more disconnected. Tambakrejo ranked 283rd in 1976-1990, 286th in 1991-2000 and 265th in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Tambakrejo had a built-up area of 4.87 square kilometers, and a population of 88542 people.

These are some other cities with approximately the same population: