Street-network Sprawl in Lere, Chad

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.

Lere: city in Mayo-Kebbi Ouest, Chad

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 Lere, Chad on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Lere as of 2014, the overall level of street-network sprawl is 0.54, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, nan, nan and nan. Data was not available in 1975, 1976-1990, 1991-2000 and 2001-2014.

Quantity of street network construction: The street network in Lere spans a total of 40 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, nan, -0.64 and 0.54. Data was not available in 1975 and 1976-1990.

Lere and Mayo-Kebbi Ouest do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, as well as the Mayo-Kebbi Ouest's street network construction.

How do development practices in Lere fare in comparison to others in Mayo-Kebbi Ouest? out of the 2 cities in Mayo-Kebbi Ouest. Lere ranked . There was no ranking in 1975, 1976-1990, 1991-2000, and 2001-2014 due to unavailable data.

Lere and Chad 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 Chad peaked in 1976-1990.

How do development practices in Lere fare in comparison to others in Chad? out of the 26 cities in Chad. Lere ranked . There was no ranking in 1975, 1976-1990, 1991-2000, and 2001-2014 due to unavailable data.

Lere and Mayo-Kebbi Ouest do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, as well as the Mayo-Kebbi Ouest's aggregate street network.

To date, Lere is the 2nd-most disconnected out of the 2 cities in Mayo-Kebbi Ouest. Its position in the ranks since 1975 has not changed. Lere ranked 2nd in 1991-2000 and 2nd in 2001-2014. There was no ranking in 1975 and 1976-1990 due to unavailable data.

Lere and Chad 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 Chad rose steadily.

To date, Lere is the 8th-most disconnected out of the 26 cities in Chad. Its position in the ranks since 1975 has risen; relative to other cities in Chad, the street network in Lere has become more disconnected. Lere ranked 17th in 1991-2000 and 8th in 2001-2014. There was no ranking in 1975 and 1976-1990 due to unavailable data.

As of 2015, Lere had a built-up area of 0.14 square kilometers, and a population of 107586 people.

These are some other cities with approximately the same population: