Street-network Sprawl in Sattur, India

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.

Sattur: city in Tamil Nadu, India

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 Sattur, India on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Sattur as of 2014, the overall level of street-network sprawl is 3.11, 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 0.56, 1.31, 4.15 and 3.48. Street construction in Sattur increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Sattur spans a total of 81 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 3.48, 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 0.56, 1.03, 2.04 and 3.11. Overall, the SNDi of the aggregate street network has risen: the street network in Sattur has become more disconnected.

Sattur and Tamil Nadu do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Sattur peaked in 1991-2000, while the SNDi of street constructions in Tamil Nadu rose steadily.

How do development practices in Sattur fare in comparison to others in Tamil Nadu? Most recently in 2001-2014, street construction in Sattur was the 69th-most disconnected out of the 151 cities in Tamil Nadu. Its position in the ranks since 1975 has risen; relative to other cities in Tamil Nadu, street construction in Sattur has become more disconnected. Sattur ranked 73rd in 1975, 89th in 1976-1990, 37th in 1991-2000 and 69th in 2001-2014.

Sattur and India do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Sattur peaked in 1991-2000, while the SNDi of street constructions in India rose steadily.

How do development practices in Sattur fare in comparison to others in India? Most recently in 2001-2014, street construction in Sattur was the 565th-most disconnected out of the 1716 cities in India. Its position in the ranks since 1975 has risen; relative to other cities in India, street construction in Sattur has become more disconnected. Sattur ranked 717th in 1975, 901st in 1976-1990, 309th in 1991-2000 and 565th in 2001-2014.

Sattur and Tamil Nadu follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Sattur is the 60th-most disconnected out of the 151 cities in Tamil Nadu. Its position in the ranks since 1975 has risen; relative to other cities in Tamil Nadu, the street network in Sattur has become more disconnected. Sattur ranked 73rd in 1975, 109th in 1976-1990, 95th in 1991-2000 and 60th in 2001-2014.

Sattur and India follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Sattur is the 607th-most disconnected out of the 1716 cities in India. Its position in the ranks since 1975 has risen; relative to other cities in India, the street network in Sattur has become more disconnected. Sattur ranked 717th in 1975, 1054th in 1976-1990, 870th in 1991-2000 and 607th in 2001-2014.

As of 2015, Sattur had a built-up area of 3.11 square kilometers, and a population of 76579 people.

These are some other cities with approximately the same population: