Street-network Sprawl in Rayong, Thailand

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.

Rayong: region in Thailand

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 Rayong, Thailand on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Rayong as of 2014, the overall level of street-network sprawl is 3.77, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.12, 3.41, 4.07 and 4.68. In each period, new street development in Rayong steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Rayong spans a total of 3037 kilometers. The period with the greatest volume of street construction was 2001-2014. These roads have an SNDi of 4.68, 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 3.12, 3.29, 3.4 and 3.77. Overall, the SNDi of the aggregate street network has risen: the street network in Rayong has become more disconnected.

The level of street-network sprawl in new development in Rayong rose steadily. To get a sense of how street development has changed in Rayong, we can consider two of its most populous cities: Rayong and Ban Map Ta Phut. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Rayong followed a zig-zag trend with an overall increase. The level of street-network sprawl in new development in Ban Map Ta Phut followed a zig-zag trend with an overall increase.

How do development practices in Rayong fare in comparison to others in Thailand? Most recently in 2001-2014, street construction in Rayong was the 31st-most disconnected out of the 36 regions in Thailand. Its position in the ranks since 1975 has fallen; relative to other regions in Thailand, street construction in Rayong has become more connected. Rayong ranked 26th in 1975, 28th in 1976-1990, 30th in 1991-2000 and 31st in 2001-2014.

As of 2014, the city with the most disconnected street network in Rayong is Rayong with an SNDi of 3.31, which is highly disconnected. Conversely, the most connected city is Ban Map Ta Phut with an SNDi of 2.13, which is relatively well-connected. See trends for these cities: Ban Map Ta Phut, Rayong

The level of street-network sprawl in the aggregate network in Rayong rose steadily. To get a sense of how the aggregate street network has changed in Rayong, we can consider two of its most populous cities: Rayong and Ban Map Ta Phut. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in the aggregate network in Rayong followed a zig-zag trend with an overall increase. The level of street-network sprawl in the aggregate network in Ban Map Ta Phut followed a zig-zag trend with an overall increase.

To date, Rayong is the 28th-most disconnected out of the 36 regions in Thailand. Its position in the ranks since 1975 has fallen; relative to other regions in Thailand, the street network in Rayong has become more connected. Rayong ranked 26th in 1975, 29th in 1976-1990, 29th in 1991-2000 and 28th in 2001-2014.