Street-network Sprawl in Dalat, 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.

Dalat: city in Lâm Đồng, 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 Dalat, Vietnam on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Dalat as of 2014, the overall level of street-network sprawl is 4.59, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 4.33, 4.56, 7.11 and 6.01. Street construction in Dalat 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 Dalat spans a total of 279 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 4.33, 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 4.33, 4.38, 4.5 and 4.59. Overall, the SNDi of the aggregate street network has risen: the street network in Dalat has become more disconnected.

Dalat and Lâm Đồng do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Dalat peaked in 1991-2000, while the SNDi of street constructions in Lâm Đồng was at its lowest in 1976-1990.

How do development practices in Dalat fare in comparison to others in Lâm Đồng? Most recently in 2001-2014, street construction in Dalat was the 1st-most disconnected out of the 5 cities in Lâm Đồng. Its position in the ranks since 1975 has not changed. Dalat ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

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

How do development practices in Dalat fare in comparison to others in Vietnam? Most recently in 2001-2014, street construction in Dalat was the 5th-most disconnected out of the 129 cities in Vietnam. Its position in the ranks since 1975 has risen; relative to other cities in Vietnam, street construction in Dalat has become more disconnected. Dalat ranked 15th in 1975, 11th in 1976-1990, 2nd in 1991-2000 and 5th in 2001-2014.

Dalat and Lâm Đồng do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Dalat rose steadily, while the SNDi of street constructions in Lâm Đồng was at its lowest in 1976-1990.

To date, Dalat is the 1st-most disconnected out of the 5 cities in Lâm Đồng. Its position in the ranks since 1975 has not changed. Dalat ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

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

To date, Dalat is the 9th-most disconnected out of the 129 cities in Vietnam. Its position in the ranks since 1975 has risen; relative to other cities in Vietnam, the street network in Dalat has become more disconnected. Dalat ranked 15th in 1975, 11th in 1976-1990, 11th in 1991-2000 and 9th in 2001-2014.

As of 2015, Dalat had a built-up area of 11.33 square kilometers, and a population of 195370 people.

These are some other cities with approximately the same population: