Street-network Sprawl in 新宁镇, 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.

新宁镇: city in Sichuan, 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 新宁镇, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in 新宁镇 as of 2014, the overall level of street-network sprawl is 2.38, 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 4.22, 3.43, 0.62 and 3.72. The disconnectivity of new streets constructed in 新宁镇 fell, then rose. In 1991-2000, new street layouts were the most connected.

Quantity of street network construction: The street network in 新宁镇 spans a total of 123 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 3.72, 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 4.22, 3.74, 1.59 and 2.38. The SNDi of the aggregate street network in fell at first, but 新宁镇 has worsened in disconnectivity since 2000.

新宁镇 and Sichuan follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these was at its lowest in 1991-2000.

How do development practices in 新宁镇 fare in comparison to others in Sichuan? Most recently in 2001-2014, street construction in 新宁镇 was the 20th-most disconnected out of the 102 cities in Sichuan. Its position in the ranks since 1975 has fallen; relative to other cities in Sichuan, street construction in 新宁镇 has become more connected. 新宁镇 ranked 8th in 1975, 17th in 1976-1990, 59th in 1991-2000 and 20th in 2001-2014.

新宁镇 and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in 新宁镇 was at its lowest 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 新宁镇 fare in comparison to others in China? Most recently in 2001-2014, street construction in 新宁镇 was the 234th-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 新宁镇 has become more connected. 新宁镇 ranked 94th in 1975, 226th in 1976-1990, 919th in 1991-2000 and 234th in 2001-2014.

新宁镇 and Sichuan follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these was at its lowest in 1991-2000.

To date, 新宁镇 is the 47th-most disconnected out of the 102 cities in Sichuan. Its position in the ranks since 1975 has fallen; relative to other cities in Sichuan, the street network in 新宁镇 has become more connected. 新宁镇 ranked 8th in 1975, 13th in 1976-1990, 57th in 1991-2000 and 47th in 2001-2014.

新宁镇 and China do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in 新宁镇 was at its lowest in 1991-2000, while the SNDi of street constructions in China peaked in 1976-1990.

To date, 新宁镇 is the 539th-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 新宁镇 has become more connected. 新宁镇 ranked 94th in 1975, 129th in 1976-1990, 854th in 1991-2000 and 539th in 2001-2014.

As of 2015, 新宁镇 had a built-up area of 4.14 square kilometers, and a population of 102347 people.

These are some other cities with approximately the same population: