Street-network Sprawl in Yangluo, China

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.

Yangluo: city in Hubei, China

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 Yangluo, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Yangluo as of 2014, the overall level of street-network sprawl is 2.84, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.02, 3.61, 2.41 and 2.48. Disconnectivity in street construction in Yangluo follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 1976-1990.

Quantity of street network construction: The street network in Yangluo spans a total of 186 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.48, 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 3.02, 3.61, 3.25 and 2.84. The aggregate street network in Yangluo increased in disconnectivity initially,but the trend has turned around after 1990.

Yangluo and Hubei do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Yangluo followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Hubei peaked in 1976-1990.

How do development practices in Yangluo fare in comparison to others in Hubei? Most recently in 2001-2014, street construction in Yangluo was the 36th-most disconnected out of the 80 cities in Hubei. Its position in the ranks since 1975 has fallen; relative to other cities in Hubei, street construction in Yangluo has become more connected. Yangluo ranked 9th in 1975, 5th in 1976-1990, 27th in 1991-2000 and 36th in 2001-2014.

Yangluo and China follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall decrease.

How do development practices in Yangluo fare in comparison to others in China? Most recently in 2001-2014, street construction in Yangluo was the 520th-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has fallen; relative to other cities in China, street construction in Yangluo has become more connected. Yangluo ranked 240th in 1975, 195th in 1976-1990, 376th in 1991-2000 and 520th in 2001-2014.

Yangluo and Hubei follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1976-1990.

To date, Yangluo is the 19th-most disconnected out of the 80 cities in Hubei. Its position in the ranks since 1975 has fallen; relative to other cities in Hubei, the street network in Yangluo has become more connected. Yangluo ranked 9th in 1975, 6th in 1976-1990, 9th in 1991-2000 and 19th in 2001-2014.

Yangluo and China follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1976-1990.

To date, Yangluo is the 343rd-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has fallen; relative to other cities in China, the street network in Yangluo has become more connected. Yangluo ranked 240th in 1975, 156th in 1976-1990, 201st in 1991-2000 and 343rd in 2001-2014.

As of 2015, Yangluo had a built-up area of 11.71 square kilometers, and a population of 89174 people.

These are some other cities with approximately the same population: