Street-network Sprawl in Chuzhou, 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.

Chuzhou: city in Anhui, 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 Chuzhou, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Chuzhou 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 1.99, 1.92, 1.16 and 0.7. In each period, new street development in Chuzhou steadily grows more connected than in the last. This decrease has quickened: between 1975 and 1976-1990, SNDi fell by 0.07 points, but between 1991-2000 and 2001-2014, it fell by just 0.46.

Quantity of street network construction: The street network in Chuzhou spans a total of 356 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 0.7, 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 1.99, 1.94, 1.83 and 1.38. Overall, the SNDi of the aggregate street network has fallen: the street network in Chuzhou has become more connected. This decrease has quickened: between 1975 and 1976-1990, SNDi fell by 0.05 points, but between 1991-2000 and 2001-2014, it fell by just 0.45.

Chuzhou and Anhui follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these fell steadily.

How do development practices in Chuzhou fare in comparison to others in Anhui? Most recently in 2001-2014, street construction in Chuzhou was the 40th-most disconnected out of the 65 cities in Anhui. Its position in the ranks since 1975 has fallen; relative to other cities in Anhui, street construction in Chuzhou has become more connected. Chuzhou ranked 17th in 1975, 18th in 1976-1990, 21st in 1991-2000 and 40th in 2001-2014.

Chuzhou and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Chuzhou fell steadily, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Chuzhou fare in comparison to others in China? Most recently in 2001-2014, street construction in Chuzhou was the 1110th-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 Chuzhou has become more connected. Chuzhou ranked 499th in 1975, 692nd in 1976-1990, 736th in 1991-2000 and 1110th in 2001-2014.

Chuzhou and Anhui follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these fell steadily.

To date, Chuzhou is the 26th-most disconnected out of the 65 cities in Anhui. Its position in the ranks since 1975 has fallen; relative to other cities in Anhui, the street network in Chuzhou has become more connected. Chuzhou ranked 17th in 1975, 15th in 1976-1990, 18th in 1991-2000 and 26th in 2001-2014.

Chuzhou and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Chuzhou fell steadily, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Chuzhou is the 1025th-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 Chuzhou has become more connected. Chuzhou ranked 499th in 1975, 680th in 1976-1990, 738th in 1991-2000 and 1025th in 2001-2014.

As of 2015, Chuzhou had a built-up area of 44.97 square kilometers, and a population of 346752 people.

These are some other cities with approximately the same population: