Street-network Sprawl in Tra On, 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.

Tra On: city in Vĩnh Long, 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 Tra On, Vietnam on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Tra On as of 2014, the overall level of street-network sprawl is 2.21, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.02, 2.94, nan and 0.9. Data was not available in 1991-2000.

Quantity of street network construction: The street network in Tra On spans a total of 29 kilometers. The period with the greatest volume of street construction was 1991-2000. These roads have an SNDi of nan, 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 2.02, 2.24, 2.27 and 2.21. The aggregate street network in Tra On increased in disconnectivity initially,but the trend has turned around after 2000.

Tra On and Vĩnh Long do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Vĩnh Long peaked in 1976-1990.

How do development practices in Tra On fare in comparison to others in Vĩnh Long? Most recently in 2001-2014, street construction in Tra On was the 2nd-most disconnected out of the 2 cities in Vĩnh Long. Its position in the ranks since 1975 has not changed. Tra On ranked 1st in 1975, 1st in 1976-1990 and 2nd in 2001-2014. There was no ranking in 1991-2000 due to unavailable data.

Tra On and Vietnam do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Vietnam rose steadily.

How do development practices in Tra On fare in comparison to others in Vietnam? Most recently in 2001-2014, street construction in Tra On was the 96th-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 Tra On has become more disconnected. Tra On ranked 40th in 1975, 37th in 1976-1990 and 96th in 2001-2014. There was no ranking in 1991-2000 due to unavailable data.

Tra On and Vĩnh Long follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these peaked in 1991-2000.

To date, Tra On is the 1st-most disconnected out of the 2 cities in Vĩnh Long. Its position in the ranks since 1975 has not changed. Tra On ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

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

To date, Tra On is the 70th-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 Tra On has become more connected. Tra On ranked 40th in 1975, 52nd in 1976-1990, 57th in 1991-2000 and 70th in 2001-2014.

As of 2015, Tra On had a built-up area of 0.56 square kilometers, and a population of 66610 people.

These are some other cities with approximately the same population: