Street-network Sprawl in Thalaiyuthu, 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.

Thalaiyuthu: 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 Thalaiyuthu, India on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Thalaiyuthu as of 2014, the overall level of street-network sprawl is 5.2, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 6.06, 1.69, 7.4 and 5.05. Disconnectivity in street construction in Thalaiyuthu follows a zig-zag trend. In 1976-1990, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Thalaiyuthu spans a total of 78 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 5.05, 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 6.06, 4.89, 5.67 and 5.2. Disconnectivity in Thalaiyuthu's street network follows a zig-zag trend. In 1976-1990, the city was most disconnected; while it was most connected in 1975.

Thalaiyuthu and Tamil Nadu do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Thalaiyuthu followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Tamil Nadu rose steadily.

How do development practices in Thalaiyuthu fare in comparison to others in Tamil Nadu? Most recently in 2001-2014, street construction in Thalaiyuthu was the 24th-most disconnected out of the 151 cities in Tamil Nadu. Its position in the ranks since 1975 has fallen; relative to other cities in Tamil Nadu, street construction in Thalaiyuthu has become more connected. Thalaiyuthu ranked 4th in 1975, 81st in 1976-1990, 4th in 1991-2000 and 24th in 2001-2014.

Thalaiyuthu and India do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Thalaiyuthu followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in India rose steadily.

How do development practices in Thalaiyuthu fare in comparison to others in India? Most recently in 2001-2014, street construction in Thalaiyuthu was the 231st-most disconnected out of the 1716 cities in India. Its position in the ranks since 1975 has fallen; relative to other cities in India, street construction in Thalaiyuthu has become more connected. Thalaiyuthu ranked 41st in 1975, 797th in 1976-1990, 34th in 1991-2000 and 231st in 2001-2014.

Thalaiyuthu and Tamil Nadu do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Thalaiyuthu followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Tamil Nadu rose steadily.

To date, Thalaiyuthu is the 6th-most disconnected out of the 151 cities in Tamil Nadu. Its position in the ranks since 1975 has fallen; relative to other cities in Tamil Nadu, the street network in Thalaiyuthu has become more connected. Thalaiyuthu ranked 4th in 1975, 7th in 1976-1990, 5th in 1991-2000 and 6th in 2001-2014.

Thalaiyuthu and India do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Thalaiyuthu followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in India rose steadily.

To date, Thalaiyuthu is the 102nd-most disconnected out of the 1716 cities in India. Its position in the ranks since 1975 has fallen; relative to other cities in India, the street network in Thalaiyuthu has become more connected. Thalaiyuthu ranked 41st in 1975, 87th in 1976-1990, 54th in 1991-2000 and 102nd in 2001-2014.

As of 2015, Thalaiyuthu had a built-up area of 1.75 square kilometers, and a population of 193879 people.

These are some other cities with approximately the same population: