Street-network Sprawl in Ikire, Nigeria

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.

Ikire: city in Osun, Nigeria

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 Ikire, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Ikire as of 2014, the overall level of street-network sprawl is 3.92, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 3.22, 3.78, 5.2 and 5.83. In each period, new street development in Ikire steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Ikire spans a total of 293 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 3.22, which is in the 40th to 60th percentile of disconnectedness.

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 3.22, 3.32, 3.35 and 3.92. Overall, the SNDi of the aggregate street network has risen: the street network in Ikire has become more disconnected.

Ikire and Osun follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these rose steadily.

How do development practices in Ikire fare in comparison to others in Osun? Most recently in 2001-2014, street construction in Ikire was the 7th-most disconnected out of the 15 cities in Osun. Its position in the ranks since 1975 has fallen; relative to other cities in Osun, street construction in Ikire has become more connected. Ikire ranked 6th in 1975, 7th in 1976-1990, 4th in 1991-2000 and 7th in 2001-2014.

Ikire and Nigeria do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Ikire rose steadily, while the SNDi of street constructions in Nigeria peaked in 1991-2000.

How do development practices in Ikire fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Ikire was the 49th-most disconnected out of the 411 cities in Nigeria. Its position in the ranks since 1975 has fallen; relative to other cities in Nigeria, street construction in Ikire has become more connected. Ikire ranked 39th in 1975, 63rd in 1976-1990, 43rd in 1991-2000 and 49th in 2001-2014.

Ikire and Osun follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Ikire is the 8th-most disconnected out of the 15 cities in Osun. Its position in the ranks since 1975 has fallen; relative to other cities in Osun, the street network in Ikire has become more connected. Ikire ranked 6th in 1975, 7th in 1976-1990, 8th in 1991-2000 and 8th in 2001-2014.

Ikire and Nigeria follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Ikire is the 69th-most disconnected out of the 411 cities in Nigeria. Its position in the ranks since 1975 has fallen; relative to other cities in Nigeria, the street network in Ikire has become more connected. Ikire ranked 39th in 1975, 59th in 1976-1990, 67th in 1991-2000 and 69th in 2001-2014.

As of 2015, Ikire had a built-up area of 14.53 square kilometers, and a population of 223138 people.

These are some other cities with approximately the same population: