Street-network Sprawl in Quanjiao, 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.

Quanjiao: 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 Quanjiao, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Quanjiao as of 2014, the overall level of street-network sprawl is 0.4, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.5, 0.83, 1.22 and -0.06. Street construction in Quanjiao increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Quanjiao spans a total of 176 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of -0.06, which is very 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 0.5, 0.69, 0.76 and 0.4. The aggregate street network in Quanjiao increased in disconnectivity initially,but the trend has turned around after 2000.

Quanjiao and Anhui do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Quanjiao peaked in 1991-2000, while the SNDi of street constructions in Anhui fell steadily.

How do development practices in Quanjiao fare in comparison to others in Anhui? Most recently in 2001-2014, street construction in Quanjiao was the 54th-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 Quanjiao has become more connected. Quanjiao ranked 32nd in 1975, 40th in 1976-1990, 18th in 1991-2000 and 54th in 2001-2014.

Quanjiao and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Quanjiao peaked in 1991-2000, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Quanjiao fare in comparison to others in China? Most recently in 2001-2014, street construction in Quanjiao was the 1298th-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 Quanjiao has become more connected. Quanjiao ranked 997th in 1975, 1121st in 1976-1990, 707th in 1991-2000 and 1298th in 2001-2014.

Quanjiao and Anhui do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Quanjiao peaked in 1991-2000, while the SNDi of street constructions in Anhui fell steadily.

To date, Quanjiao is the 51st-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 Quanjiao has become more connected. Quanjiao ranked 32nd in 1975, 44th in 1976-1990, 37th in 1991-2000 and 51st in 2001-2014.

Quanjiao and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Quanjiao peaked in 1991-2000, while the SNDi of street constructions in China peaked in 1976-1990.

To date, Quanjiao is the 1448th-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 Quanjiao has become more connected. Quanjiao ranked 997th in 1975, 1281st in 1976-1990, 1264th in 1991-2000 and 1448th in 2001-2014.

As of 2015, Quanjiao had a built-up area of 11.76 square kilometers, and a population of 122176 people.

These are some other cities with approximately the same population: