Street-network Sprawl in Léogâne, Haiti

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.

Léogâne: city in Ouest, Haiti

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 Léogâne, Haiti on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Léogâne as of 2014, the overall level of street-network sprawl is 2.61, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, 1.07, 5.15 and 3.66. Data was not available in 1975.

Quantity of street network construction: The street network in Léogâne spans a total of 89 kilometers. It is dominated by roads constructed prior to 1975. 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 nan, 1.07, 2.02 and 2.61. Data was not available in 1975.

Léogâne and Ouest 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 Ouest peaked in 1991-2000.

How do development practices in Léogâne fare in comparison to others in Ouest? Most recently in 2001-2014, street construction in Léogâne was the 3rd-most disconnected out of the 6 cities in Ouest. Its position in the ranks since 1975 has risen; relative to other cities in Ouest, street construction in Léogâne has become more disconnected. Léogâne ranked 6th in 1976-1990, 3rd in 1991-2000 and 3rd in 2001-2014. There was no ranking in 1975 due to unavailable data.

Léogâne and Haiti 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 Haiti peaked in 1991-2000.

How do development practices in Léogâne fare in comparison to others in Haiti? Most recently in 2001-2014, street construction in Léogâne was the 9th-most disconnected out of the 22 cities in Haiti. Its position in the ranks since 1975 has risen; relative to other cities in Haiti, street construction in Léogâne has become more disconnected. Léogâne ranked 15th in 1976-1990, 4th in 1991-2000 and 9th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Léogâne and Ouest do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Ouest peaked in 1991-2000.

To date, Léogâne is the 6th-most disconnected out of the 6 cities in Ouest. Its position in the ranks since 1975 has not changed. Léogâne ranked 6th in 1976-1990, 6th in 1991-2000 and 6th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Léogâne and Haiti do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Haiti rose steadily.

To date, Léogâne is the 12th-most disconnected out of the 22 cities in Haiti. Its position in the ranks since 1975 has risen; relative to other cities in Haiti, the street network in Léogâne has become more disconnected. Léogâne ranked 18th in 1976-1990, 13th in 1991-2000 and 12th in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Léogâne had a built-up area of 2.35 square kilometers, and a population of 132814 people.

These are some other cities with approximately the same population: