Street-network Sprawl in Bình Thuận, 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.

Bình Thuận: 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 Bình Thuận, Vietnam on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Bình Thuận as of 2014, the overall level of street-network sprawl is 3.27, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.6, 2.81, 3.26 and 3.93. In each period, new street development in Bình Thuận steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Bình Thuận spans a total of 3793 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 3.93, 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 2.6, 2.6, 2.8 and 3.27. Overall, the SNDi of the aggregate street network has risen: the street network in Bình Thuận has become more disconnected.

The level of street-network sprawl in new development in Bình Thuận rose steadily. To get a sense of how street development has changed in Bình Thuận, we can consider three of its most populous cities: Phan Thiet, La Gi and Phan Rí Cửa. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Phan Thiet peaked in 1976-1990. The level of street-network sprawl in new development in La Gi was at its lowest in 1976-1990. The level of street-network sprawl in new development in Phan Rí Cửa followed a zig-zag trend.

How do development practices in Bình Thuận fare in comparison to others in Vietnam? Most recently in 2001-2014, street construction in Bình Thuận was the 27th-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 Bình Thuận has become more connected. Bình Thuận ranked 25th in 1975, 27th in 1976-1990, 32nd in 1991-2000 and 27th in 2001-2014.

As of 2014, the city with the most disconnected street network in Bình Thuận is La Gi with an SNDi of 3.37, which is highly disconnected. Conversely, the most connected city is Phan Rí Cửa with an SNDi of 2.05, which is relatively well-connected. See trends for these cities: Phan Rí Cửa, La Gi

The level of street-network sprawl in the aggregate network in Bình Thuận rose steadily. To get a sense of how the aggregate street network has changed in Bình Thuận, we can consider three of its most populous cities: Phan Thiet, La Gi and Phan Rí Cửa. Out of the three cities, La Gi and Phan Rí Cửa do not follow the same trend as the region. The level of street-network sprawl in the aggregate network in La Gi followed a zig-zag trend with an overall decrease. The level of street-network sprawl in the aggregate network in Phan Rí Cửa rose steadily.

To date, Bình Thuận is the 35th-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 Bình Thuận has become more connected. Bình Thuận ranked 25th in 1975, 33rd in 1976-1990, 34th in 1991-2000 and 35th in 2001-2014.