Street-network Sprawl in Liaoyang, 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.

Liaoyang: city in Liaoning, 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 Liaoyang, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Liaoyang as of 2014, the overall level of street-network sprawl is 1.38, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.76, 1.71, -0.22 and 2.18. Disconnectivity in street construction in Liaoyang follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 2001-2014.

Quantity of street network construction: The street network in Liaoyang spans a total of 274 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 1.71, which is relatively well-connected.

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 0.76, 1.33, 1.29 and 1.38. Disconnectivity in Liaoyang's street network follows a zig-zag trend. In 1975, the city was most disconnected; while it was most connected in 2001-2014.

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

How do development practices in Liaoyang fare in comparison to others in Liaoning? Most recently in 2001-2014, street construction in Liaoyang was the 12th-most disconnected out of the 52 cities in Liaoning. Its position in the ranks since 1975 has risen; relative to other cities in Liaoning, street construction in Liaoyang has become more disconnected. Liaoyang ranked 37th in 1975, 32nd in 1976-1990, 26th in 1991-2000 and 12th in 2001-2014.

Liaoyang 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 increase.

How do development practices in Liaoyang fare in comparison to others in China? Most recently in 2001-2014, street construction in Liaoyang was the 608th-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has risen; relative to other cities in China, street construction in Liaoyang has become more disconnected. Liaoyang ranked 915th in 1975, 777th in 1976-1990, 1136th in 1991-2000 and 608th in 2001-2014.

Liaoyang and Liaoning do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Liaoyang followed a zig-zag trend with an overall increase, while the SNDi of street constructions in Liaoning peaked in 1991-2000.

To date, Liaoyang is the 29th-most disconnected out of the 52 cities in Liaoning. Its position in the ranks since 1975 has risen; relative to other cities in Liaoning, the street network in Liaoyang has become more disconnected. Liaoyang ranked 37th in 1975, 28th in 1976-1990, 29th in 1991-2000 and 29th in 2001-2014.

Liaoyang and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Liaoyang followed a zig-zag trend with an overall increase, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Liaoyang is the 1024th-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 Liaoyang has become more connected. Liaoyang ranked 915th in 1975, 976th in 1976-1990, 1009th in 1991-2000 and 1024th in 2001-2014.

As of 2015, Liaoyang had a built-up area of 63.19 square kilometers, and a population of 619684 people.

These are some other cities with approximately the same population: