Street-network Sprawl in Huailai, 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.

Huailai: city in Hebei, 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 Huailai, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Huailai as of 2014, the overall level of street-network sprawl is 0.58, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.53, 0.36, 1.24 and 0.65. Disconnectivity in street construction in Huailai follows a zig-zag trend. In 1976-1990, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Huailai spans a total of 124 kilometers. The period with the greatest volume of street construction was 1976-1990. These roads have an SNDi of 0.36, 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 0.53, 0.39, 0.57 and 0.58. The SNDi of the aggregate street network in fell at first, but Huailai has worsened in disconnectivity since 1990.

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

How do development practices in Huailai fare in comparison to others in Hebei? Most recently in 2001-2014, street construction in Huailai was the 76th-most disconnected out of the 99 cities in Hebei. Its position in the ranks since 1975 has fallen; relative to other cities in Hebei, street construction in Huailai has become more connected. Huailai ranked 73rd in 1975, 79th in 1976-1990, 38th in 1991-2000 and 76th in 2001-2014.

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

How do development practices in Huailai fare in comparison to others in China? Most recently in 2001-2014, street construction in Huailai was the 1126th-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 Huailai has become more connected. Huailai ranked 986th in 1975, 1271st in 1976-1990, 700th in 1991-2000 and 1126th in 2001-2014.

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

To date, Huailai is the 78th-most disconnected out of the 99 cities in Hebei. Its position in the ranks since 1975 has fallen; relative to other cities in Hebei, the street network in Huailai has become more connected. Huailai ranked 73rd in 1975, 81st in 1976-1990, 78th in 1991-2000 and 78th in 2001-2014.

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

To date, Huailai is the 1406th-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 Huailai has become more connected. Huailai ranked 986th in 1975, 1377th in 1976-1990, 1340th in 1991-2000 and 1406th in 2001-2014.

As of 2015, Huailai had a built-up area of 14.37 square kilometers, and a population of 96989 people.

These are some other cities with approximately the same population: