Street-network Sprawl in Hebei, 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.

Hebei: region in 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 Hebei, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Hebei as of 2014, the overall level of street-network sprawl is 2.57, 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 2.57, 2.69, 2.15 and 2.55. Disconnectivity in street construction in Hebei follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 1976-1990.

Quantity of street network construction: The street network in Hebei spans a total of 123128 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 2.55, which is in the 40th to 60th percentile of disconnectedness.

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 2.57, 2.66, 2.58 and 2.57. The aggregate street network in Hebei increased in disconnectivity initially,but the trend has turned around after 1990.

The level of street-network sprawl in new development in Hebei followed a zig-zag trend with an overall decrease. To get a sense of how street development has changed in Hebei, we can consider three of its most populous cities: Shijiazhuang, Tangshan and Baoding. Out of the three cities, Shijiazhuang and Tangshan do not follow the same trend as the region. The level of street-network sprawl in new development in Shijiazhuang peaked in 1991-2000. The level of street-network sprawl in new development in Tangshan peaked in 1976-1990.

How do development practices in Hebei fare in comparison to others in China? Most recently in 2001-2014, street construction in Hebei was the 28th-most disconnected out of the 34 regions in China. Its position in the ranks since 1975 has fallen; relative to other regions in China, street construction in Hebei has become more connected. Hebei ranked 22nd in 1975, 28th in 1976-1990, 28th in 1991-2000 and 28th in 2001-2014.

As of 2014, the city with the most disconnected street network in Hebei is Lvjiatuo with an SNDi of 5.35, which is highly disconnected. Conversely, the most connected city is Yongqing with an SNDi of -1.57, which is very well-connected. See trends for these cities: Yongqing, Lvjiatuo

The level of street-network sprawl in the aggregate network in Hebei peaked in 1976-1990. To get a sense of how the aggregate street network has changed in Hebei, we can consider three of its most populous cities: Shijiazhuang, Tangshan and Baoding. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Shijiazhuang rose steadily. The level of street-network sprawl in the aggregate network in Tangshan peaked in 1991-2000. The level of street-network sprawl in the aggregate network in Baoding followed a zig-zag trend with an overall increase.

To date, Hebei is the 24th-most disconnected out of the 34 regions in China. Its position in the ranks since 1975 has fallen; relative to other regions in China, the street network in Hebei has become more connected. Hebei ranked 22nd in 1975, 23rd in 1976-1990, 24th in 1991-2000 and 24th in 2001-2014.