Street-network Sprawl in Afghanistan

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.

Afghanistan

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 Afghanistan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Afghanistan as of 2014, the overall level of street-network sprawl is 4.95, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 6.36, 4.13, 6.39 and 3.93. Disconnectivity in street construction in Afghanistan follows a zig-zag trend. In 2001-2014, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Afghanistan spans a total of 26230 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 6.36, 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 6.36, 5.19, 5.32 and 4.95. Disconnectivity in Afghanistan's street network follows a zig-zag trend. In 2001-2014, the country was most disconnected; while it was most connected in 1975.

The level of street-network sprawl in new development in Afghanistan followed a zig-zag trend with an overall decrease. To get a sense of how street development has changed in Afghanistan, we can consider three of its most populous regions: Kabul, Hirat and Kandahar. Out of the three regions, Kandahar does not follow the same trend as the country. The level of street-network sprawl in new development in Kandahar fell steadily.

How do development practices in Afghanistan fare in comparison to others in the world? Most recently in 2001-2014, street construction in Afghanistan was the 98th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, street construction in Afghanistan has become more connected. Afghanistan ranked 3rd in 1975, 46th in 1976-1990, 17th in 1991-2000 and 98th in 2001-2014.

The largest city in Afghanistan is Kabul, with a population of 4381800 people. Taking into account the entire (i.e. aggregate) street network in Kabul as of 2014, the overall level of street-network sprawl is 3.51, which is highly disconnected. The level of street-network sprawl in new development in Kabul followed a zig-zag trend with an overall decrease.

As of 2014, the city with the most disconnected street network in Afghanistan is Chaman with an SNDi of 12.25, which is highly disconnected. Conversely, the most connected city is Khost with an SNDi of -0.43, which is very well-connected. See trends for these cities: Khost, Chaman

The level of street-network sprawl in the aggregate network in Afghanistan followed a zig-zag trend with an overall decrease. To get a sense of how the aggregate street network has changed in Afghanistan, we can consider three of its most populous regions: Kabul, Hirat and Kandahar. Out of the three regions, Kabul and Kandahar do not follow the same trend as the country. The level of street-network sprawl in the aggregate network in Kabul was at its lowest in 1976-1990. The level of street-network sprawl in the aggregate network in Kandahar fell steadily.

To date, Afghanistan is the 28th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, the street network in Afghanistan has become more connected. Afghanistan ranked 3rd in 1975, 13th in 1976-1990, 14th in 1991-2000 and 28th in 2001-2014.

The largest city in Afghanistan is Kabul, with a population of 4381800 people. Taking into account the entire (i.e. aggregate) street network in Kabul as of 2014, the overall level of street-network sprawl is 3.51, which is highly disconnected. The level of street-network sprawl in the aggregate network in Kabul followed a zig-zag trend with an overall decrease.