Street-network Sprawl in Tangshan, 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.

Tangshan: 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 Tangshan, China on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Tangshan as of 2014, the overall level of street-network sprawl is 2.95, 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 2.65, 3.41, 3.12 and 2.79. Street construction in Tangshan increased in disconnectivity initially but has since improved. The streets constructed in 1976-1990 were the most disconnected.

Quantity of street network construction: The street network in Tangshan spans a total of 1990 kilometers. The period with the greatest volume of street construction was 1975. These roads have an SNDi of 2.65, 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 2.65, 2.99, 3.0 and 2.95. The aggregate street network in Tangshan increased in disconnectivity initially,but the trend has turned around after 2000.

Tangshan and Hebei do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Tangshan peaked in 1976-1990, while the SNDi of street constructions in Hebei followed a zig-zag trend with an overall decrease.

How do development practices in Tangshan fare in comparison to others in Hebei? Most recently in 2001-2014, street construction in Tangshan was the 26th-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 Tangshan has become more connected. Tangshan ranked 23rd in 1975, 10th in 1976-1990, 6th in 1991-2000 and 26th in 2001-2014.

Tangshan and China do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Tangshan peaked in 1976-1990, while the SNDi of street constructions in China followed a zig-zag trend with an overall decrease.

How do development practices in Tangshan fare in comparison to others in China? Most recently in 2001-2014, street construction in Tangshan was the 441st-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 Tangshan has become more connected. Tangshan ranked 319th in 1975, 229th in 1976-1990, 227th in 1991-2000 and 441st in 2001-2014.

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

To date, Tangshan is the 9th-most disconnected out of the 99 cities in Hebei. Its position in the ranks since 1975 has risen; relative to other cities in Hebei, the street network in Tangshan has become more disconnected. Tangshan ranked 23rd in 1975, 12th in 1976-1990, 9th in 1991-2000 and 9th in 2001-2014.

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

To date, Tangshan is the 303rd-most disconnected out of the 1651 cities in China. Its position in the ranks since 1975 has risen; relative to other cities in China, the street network in Tangshan has become more disconnected. Tangshan ranked 319th in 1975, 288th in 1976-1990, 272nd in 1991-2000 and 303rd in 2001-2014.

As of 2015, Tangshan had a built-up area of 195.66 square kilometers, and a population of 1578319 people.

These are some other cities with approximately the same population:

For some related information about population, urban extent and density, and roads, visit the Atlas of Urban Expansion.