Street-network Sprawl in Bahamas

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.

Bahamas

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 Bahamas on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Bahamas as of 2014, the overall level of street-network sprawl is 5.46, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 5.18, 5.14, 7.18 and 6.09. Disconnectivity in street construction in Bahamas follows a zig-zag trend. In 1976-1990, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Bahamas spans a total of 2994 kilometers. The period with the greatest volume of street construction was 1975. These roads have an SNDi of 5.18, 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 5.18, 5.2, 5.41 and 5.46. Overall, the SNDi of the aggregate street network has risen: the street network in Bahamas has become more disconnected.

The level of street-network sprawl in new development in Bahamas followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in Bahamas, we can consider one of its most populous regions: New Providence. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in New Providence peaked in 1991-2000.

How do development practices in Bahamas fare in comparison to others in the world? Most recently in 2001-2014, street construction in Bahamas was the 29th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, street construction in Bahamas has become more connected. Bahamas ranked 11th in 1975, 20th in 1976-1990, 7th in 1991-2000 and 29th in 2001-2014.

The largest city in Bahamas is Nassau, with a population of 213700 people. Taking into account the entire (i.e. aggregate) street network in Nassau as of 2014, the overall level of street-network sprawl is 4.76, which is highly disconnected. The level of street-network sprawl in new development in Nassau was at its lowest in 1976-1990.

As of 2014, the city with the most disconnected street network in Bahamas is Nassau with an SNDi of 4.76, which is highly disconnected. Conversely, the most connected city is Nassau with an SNDi of 4.76, which is highly disconnected. See trends for these cities: Nassau, Nassau

The level of street-network sprawl in the aggregate network in Bahamas rose steadily. To get a sense of how the aggregate street network has changed in Bahamas, we can consider one of its most populous regions: New Providence. Disconnectivity in the most populous cities in Bahamas follow the same country trend.

To date, Bahamas is the 14th-most disconnected out of the 155 countries in the world. Its position in the ranks since 1975 has fallen; relative to other countries in the world, the street network in Bahamas has become more connected. Bahamas ranked 11th in 1975, 12th in 1976-1990, 12th in 1991-2000 and 14th in 2001-2014.

The largest city in Bahamas is Nassau, with a population of 213700 people. Taking into account the entire (i.e. aggregate) street network in Nassau as of 2014, the overall level of street-network sprawl is 4.76, which is highly disconnected. The level of street-network sprawl in the aggregate network in Nassau was at its lowest in 1976-1990.