Street-network Sprawl in Mumbai, 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.

Mumbai: city in Maharashtra, 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 Mumbai, India on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Mumbai as of 2014, the overall level of street-network sprawl is 3.76, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.22, 4.32, 4.89 and 4.8. Street construction in Mumbai 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 Mumbai spans a total of 7610 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 3.22, which is in the 40th to 60th percentile of disconnectedness.

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 3.22, 3.67, 3.71 and 3.76. Overall, the SNDi of the aggregate street network has risen: the street network in Mumbai has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.44 points, but between 1991-2000 and 2001-2014, it rose by just 0.05.

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

How do development practices in Mumbai fare in comparison to others in Maharashtra? Most recently in 2001-2014, street construction in Mumbai was the 37th-most disconnected out of the 186 cities in Maharashtra. Its position in the ranks since 1975 has fallen; relative to other cities in Maharashtra, street construction in Mumbai has become more connected. Mumbai ranked 21st in 1975, 13th in 1976-1990, 19th in 1991-2000 and 37th in 2001-2014.

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

How do development practices in Mumbai fare in comparison to others in India? Most recently in 2001-2014, street construction in Mumbai was the 283rd-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 Mumbai has become more connected. Mumbai ranked 271st in 1975, 173rd in 1976-1990, 197th in 1991-2000 and 283rd in 2001-2014.

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

To date, Mumbai is the 34th-most disconnected out of the 186 cities in Maharashtra. Its position in the ranks since 1975 has fallen; relative to other cities in Maharashtra, the street network in Mumbai has become more connected. Mumbai ranked 21st in 1975, 22nd in 1976-1990, 28th in 1991-2000 and 34th in 2001-2014.

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

To date, Mumbai is the 374th-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 Mumbai has become more connected. Mumbai ranked 271st in 1975, 274th in 1976-1990, 319th in 1991-2000 and 374th in 2001-2014.

As of 2015, Mumbai had a built-up area of 364.17 square kilometers, and a population of 21755882 people.

These are some other cities with approximately the same population:

For some related information about population, urban extent and density, and roads, visit the Atlas of Urban Expansion.