Street-network Sprawl in Quảng Trị, 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.

Quảng Trị: region in Vietnam

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 Quảng Trị, Vietnam on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Quảng Trị as of 2014, the overall level of street-network sprawl is 3.06, 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 2.28, 1.92, 3.08 and 4.1. The disconnectivity of new streets constructed in Quảng Trị fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Quảng Trị spans a total of 2780 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 4.1, 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 2.28, 2.32, 2.53 and 3.06. Overall, the SNDi of the aggregate street network has risen: the street network in Quảng Trị has become more disconnected.

The level of street-network sprawl in new development in Quảng Trị was at its lowest in 1976-1990. To get a sense of how street development has changed in Quảng Trị, we can consider one of its most populous cities: Dong Ha. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Dong Ha followed a zig-zag trend with an overall increase.

How do development practices in Quảng Trị fare in comparison to others in Vietnam? Most recently in 2001-2014, street construction in Quảng Trị was the 23rd-most disconnected out of the 59 regions in Vietnam. Its position in the ranks since 1975 has risen; relative to other regions in Vietnam, street construction in Quảng Trị has become more disconnected. Quảng Trị ranked 31st in 1975, 48th in 1976-1990, 35th in 1991-2000 and 23rd in 2001-2014.

As of 2014, the city with the most disconnected street network in Quảng Trị is Dong Ha with an SNDi of 2.01, which is relatively well-connected. Conversely, the most connected city is Dong Ha with an SNDi of 2.01, which is relatively well-connected. See trends for these cities: Dong Ha, Dong Ha

The level of street-network sprawl in the aggregate network in Quảng Trị rose steadily. To get a sense of how the aggregate street network has changed in Quảng Trị, we can consider one of its most populous cities: Dong Ha. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Dong Ha rose steadily.

To date, Quảng Trị is the 40th-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 Quảng Trị has become more connected. Quảng Trị ranked 31st in 1975, 41st in 1976-1990, 41st in 1991-2000 and 40th in 2001-2014.