Street-network Sprawl in North Korea

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.

North Korea

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 North Korea on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in North Korea as of 2014, the overall level of street-network sprawl is 5.79, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 5.52, 6.53, 5.95 and 6.39. Disconnectivity in street construction in North Korea follows a zig-zag trend. In 1975, street construction was most disconnected, while construction was most connected in 1976-1990.

Quantity of street network construction: The street network in North Korea spans a total of 47004 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 5.52, 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 5.52, 5.69, 5.74 and 5.79. Overall, the SNDi of the aggregate street network has risen: the street network in North Korea has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.18 points, but between 1991-2000 and 2001-2014, it rose by just 0.06.

The level of street-network sprawl in new development in North Korea followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in North Korea, we can consider three of its most populous regions: P'yŏngyang, P'yŏngan-namdo and Hamgyŏng-namdo. Out of the three regions, Hamgyŏng-namdo does not follow the same trend as the country. The level of street-network sprawl in new development in Hamgyŏng-namdo rose steadily.

How do development practices in North Korea fare in comparison to others in the world? Most recently in 2001-2014, street construction in North Korea was the 19th-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 North Korea has become more connected. North Korea ranked 8th in 1975, 5th in 1976-1990, 23rd in 1991-2000 and 19th in 2001-2014.

The largest city in North Korea is Pyongyang, with a population of 2439200 people. Taking into account the entire (i.e. aggregate) street network in Pyongyang as of 2014, the overall level of street-network sprawl is 4.54, which is highly disconnected. The level of street-network sprawl in new development in Pyongyang peaked in 1991-2000.

As of 2014, the city with the most disconnected street network in North Korea is Huichon with an SNDi of 7.64, which is highly disconnected. Conversely, the most connected city is Mundok with an SNDi of -0.07, which is very well-connected. See trends for these cities: Mundok, Huichon

The level of street-network sprawl in the aggregate network in North Korea rose steadily. To get a sense of how the aggregate street network has changed in North Korea, we can consider three of its most populous regions: P'yŏngyang, P'yŏngan-namdo and Hamgyŏng-namdo. Out of the three regions, P'yŏngan-namdo does not follow the same trend as the country. The level of street-network sprawl in the aggregate network in P'yŏngan-namdo peaked in 1976-1990.

To date, North Korea is the 8th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has not changed. North Korea ranked 8th in 1975, 7th in 1976-1990, 8th in 1991-2000 and 8th in 2001-2014.

The largest city in North Korea is Pyongyang, with a population of 2439200 people. Taking into account the entire (i.e. aggregate) street network in Pyongyang as of 2014, the overall level of street-network sprawl is 4.54, which is highly disconnected. The level of street-network sprawl in the aggregate network in Pyongyang rose steadily.