Street-network Sprawl in Nepal

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.

Nepal

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 Nepal on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Nepal as of 2014, the overall level of street-network sprawl is 4.55, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 4.2, 4.0, 4.02 and 5.14. The disconnectivity of new streets constructed in Nepal fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Nepal spans a total of 28920 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 5.14, 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 4.2, 4.29, 4.3 and 4.55. Overall, the SNDi of the aggregate street network has risen: the street network in Nepal has become more disconnected.

The level of street-network sprawl in new development in Nepal was at its lowest in 1976-1990. To get a sense of how street development has changed in Nepal, we can consider three of its most populous regions: Central, East and West. Out of the three regions, West does not follow the same trend as the country. The level of street-network sprawl in new development in West followed a zig-zag trend with an overall increase.

How do development practices in Nepal fare in comparison to others in the world? Most recently in 2001-2014, street construction in Nepal was the 51st-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 Nepal has become more connected. Nepal ranked 36th in 1975, 47th in 1976-1990, 79th in 1991-2000 and 51st in 2001-2014.

The largest city in Nepal is Kathmandu, with a population of 3529100 people. Taking into account the entire (i.e. aggregate) street network in Kathmandu as of 2014, the overall level of street-network sprawl is 3.81, which is highly disconnected. The level of street-network sprawl in new development in Kathmandu followed a zig-zag trend with an overall increase.

As of 2014, the city with the most disconnected street network in Nepal is Kathmandu with an SNDi of 3.81, which is highly disconnected. Conversely, the most connected city is Tulsipur with an SNDi of 1.03, which is relatively well-connected. See trends for these cities: Tulsipur, Kathmandu

The level of street-network sprawl in the aggregate network in Nepal rose steadily. To get a sense of how the aggregate street network has changed in Nepal, we can consider three of its most populous regions: Central, East and West. Out of the three regions, East does not follow the same trend as the country. The level of street-network sprawl in the aggregate network in East was at its lowest in 1976-1990.

To date, Nepal is the 39th-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 Nepal has become more connected. Nepal ranked 36th in 1975, 36th in 1976-1990, 41st in 1991-2000 and 39th in 2001-2014.

The largest city in Nepal is Kathmandu, with a population of 3529100 people. Taking into account the entire (i.e. aggregate) street network in Kathmandu as of 2014, the overall level of street-network sprawl is 3.81, which is highly disconnected. The level of street-network sprawl in the aggregate network in Kathmandu was at its lowest in 1976-1990.