Street-network Sprawl in Filingué, Niger

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.

Filingué: city in Tillabéry, Niger

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 Filingué, Niger on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Filingué as of 2014, the overall level of street-network sprawl is 0.14, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.01, 0.01, -0.84 and 0.76. The disconnectivity of new streets constructed in Filingué fell, then rose. In 1991-2000, new street layouts were the most connected.

Quantity of street network construction: The street network in Filingué spans a total of 109 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 0.01, which is very well-connected.

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 1.01, 0.32, -0.04 and 0.14. The SNDi of the aggregate street network in fell at first, but Filingué has worsened in disconnectivity since 2000.

Filingué and Tillabéry do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Filingué was at its lowest in 1991-2000, while the SNDi of street constructions in Tillabéry was at its lowest in 1976-1990.

How do development practices in Filingué fare in comparison to others in Tillabéry? Most recently in 2001-2014, street construction in Filingué was the 4th-most disconnected out of the 6 cities in Tillabéry. Its position in the ranks since 1975 has fallen; relative to other cities in Tillabéry, street construction in Filingué has become more connected. Filingué ranked 1st in 1975, 3rd in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014.

Filingué and Niger do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Filingué was at its lowest in 1991-2000, while the SNDi of street constructions in Niger rose steadily.

How do development practices in Filingué fare in comparison to others in Niger? Most recently in 2001-2014, street construction in Filingué was the 8th-most disconnected out of the 21 cities in Niger. Its position in the ranks since 1975 has fallen; relative to other cities in Niger, street construction in Filingué has become more connected. Filingué ranked 1st in 1975, 7th in 1976-1990, 16th in 1991-2000 and 8th in 2001-2014.

Filingué and Tillabéry do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Filingué was at its lowest in 1991-2000, while the SNDi of street constructions in Tillabéry was at its lowest in 1976-1990.

To date, Filingué is the 5th-most disconnected out of the 6 cities in Tillabéry. Its position in the ranks since 1975 has fallen; relative to other cities in Tillabéry, the street network in Filingué has become more connected. Filingué ranked 1st in 1975, 2nd in 1976-1990, 4th in 1991-2000 and 5th in 2001-2014.

Filingué and Niger do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Filingué was at its lowest in 1991-2000, while the SNDi of street constructions in Niger rose steadily.

To date, Filingué is the 12th-most disconnected out of the 21 cities in Niger. Its position in the ranks since 1975 has fallen; relative to other cities in Niger, the street network in Filingué has become more connected. Filingué ranked 1st in 1975, 5th in 1976-1990, 14th in 1991-2000 and 12th in 2001-2014.

As of 2015, Filingué had a built-up area of 1.36 square kilometers, and a population of 73320 people.

These are some other cities with approximately the same population: