Street-network Sprawl in Đà Nẵng, 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.

Đà Nẵng: city 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 Đà Nẵng, Vietnam on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Đà Nẵng as of 2014, the overall level of street-network sprawl is 1.65, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.51, 2.58, 3.3 and 1.77. Street construction in Đà Nẵng increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Đà Nẵng spans a total of 1574 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.51, which is relatively well-connected.

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 1.51, 1.54, 1.6 and 1.65. Overall, the SNDi of the aggregate street network has risen: the street network in Đà Nẵng has become more disconnected.

Đà Nẵng and Đà Nẵng follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these peaked in 1991-2000.

How do development practices in Đà Nẵng fare in comparison to others in Đà Nẵng? Most recently in 2001-2014, street construction in Đà Nẵng was the 1st-most disconnected out of the 1 cities in Đà Nẵng. Its position in the ranks since 1975 has not changed. Đà Nẵng ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Đà Nẵng and Vietnam do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Đà Nẵng peaked in 1991-2000, while the SNDi of street constructions in Vietnam rose steadily.

How do development practices in Đà Nẵng fare in comparison to others in Vietnam? Most recently in 2001-2014, street construction in Đà Nẵng was the 84th-most disconnected out of the 129 cities in Vietnam. Its position in the ranks since 1975 has fallen; relative to other cities in Vietnam, street construction in Đà Nẵng has become more connected. Đà Nẵng ranked 55th in 1975, 44th in 1976-1990, 30th in 1991-2000 and 84th in 2001-2014.

Đà Nẵng and Đà Nẵng follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Đà Nẵng is the 1st-most disconnected out of the 1 cities in Đà Nẵng. Its position in the ranks since 1975 has not changed. Đà Nẵng ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Đà Nẵng and Vietnam follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Đà Nẵng is the 87th-most disconnected out of the 129 cities in Vietnam. Its position in the ranks since 1975 has fallen; relative to other cities in Vietnam, the street network in Đà Nẵng has become more connected. Đà Nẵng ranked 55th in 1975, 78th in 1976-1990, 83rd in 1991-2000 and 87th in 2001-2014.

As of 2015, Đà Nẵng had a built-up area of 77.37 square kilometers, and a population of 1003279 people.

These are some other cities with approximately the same population: