Street-network Sprawl in Guangxi, Vietnam

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.

Guangxi: region in Vietnam

View Guangxi, Vietnam on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Guangxi as of 2014, the overall level of street-network sprawl is 3.79, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.61, 4.21, 3.28 and 3.66. Disconnectivity in street construction in Guangxi 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 Guangxi spans a total of 59534 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 3.66, 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 3.61, 4.06, 3.88 and 3.79. The aggregate street network in Guangxi increased in disconnectivity initially,but the trend has turned around after 1990.

The level of street-network sprawl in new development in Guangxi followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in Guangxi, we can consider one of its most populous cities: Mong Cai. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Mong Cai was at its lowest in 1991-2000.

How do development practices in Guangxi fare in comparison to others in Vietnam? Most recently in 2001-2014, street construction in Guangxi was the 37th-most disconnected out of the 59 regions in Vietnam. Its position in the ranks since 1975 has fallen; relative to other regions in Vietnam, street construction in Guangxi has become more connected. Guangxi ranked 14th in 1975, 12th in 1976-1990, 30th in 1991-2000 and 37th in 2001-2014.

As of 2014, the city with the most disconnected street network in Guangxi is Mong Cai with an SNDi of 2.24, which is relatively well-connected. Conversely, the most connected city is Mong Cai with an SNDi of 2.24, which is relatively well-connected. See trends for these cities: Mong Cai, Mong Cai

The level of street-network sprawl in the aggregate network in Guangxi peaked in 1976-1990. To get a sense of how the aggregate street network has changed in Guangxi, we can consider one of its most populous cities: Mong Cai. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Mong Cai was at its lowest in 1991-2000.

To date, Guangxi is the 18th-most disconnected out of the 59 regions in Vietnam. Its position in the ranks since 1975 has fallen; relative to other regions in Vietnam, the street network in Guangxi has become more connected. Guangxi ranked 14th in 1975, 12th in 1976-1990, 15th in 1991-2000 and 18th in 2001-2014.