Street-network Sprawl in Igbeti, 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.

Igbeti: city in Oyo, 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 Igbeti, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Igbeti as of 2014, the overall level of street-network sprawl is 1.53, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.1, 10.97, 0.84 and 1.39. Disconnectivity in street construction in Igbeti follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 1976-1990.

Quantity of street network construction: The street network in Igbeti spans a total of 96 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 1.39, which is relatively 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 2.1, 2.25, 2.22 and 1.53. The aggregate street network in Igbeti increased in disconnectivity initially,but the trend has turned around after 1990.

Igbeti and Oyo follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall decrease.

How do development practices in Igbeti fare in comparison to others in Oyo? Most recently in 2001-2014, street construction in Igbeti was the 11th-most disconnected out of the 15 cities in Oyo. Its position in the ranks since 1975 has fallen; relative to other cities in Oyo, street construction in Igbeti has become more connected. Igbeti ranked 5th in 1975, 1st in 1976-1990, 9th in 1991-2000 and 11th in 2001-2014.

Igbeti and Nigeria do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Igbeti followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Nigeria peaked in 1991-2000.

How do development practices in Igbeti fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Igbeti was the 263rd-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 Igbeti has become more connected. Igbeti ranked 82nd in 1975, 2nd in 1976-1990, 209th in 1991-2000 and 263rd in 2001-2014.

Igbeti and Oyo do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Igbeti peaked in 1976-1990, while the SNDi of street constructions in Oyo followed a zig-zag trend with an overall increase.

To date, Igbeti is the 9th-most disconnected out of the 15 cities in Oyo. Its position in the ranks since 1975 has fallen; relative to other cities in Oyo, the street network in Igbeti has become more connected. Igbeti ranked 5th in 1975, 4th in 1976-1990, 4th in 1991-2000 and 9th in 2001-2014.

Igbeti and Nigeria do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Igbeti peaked in 1976-1990, while the SNDi of street constructions in Nigeria rose steadily.

To date, Igbeti is the 232nd-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 Igbeti has become more connected. Igbeti ranked 82nd in 1975, 132nd in 1976-1990, 150th in 1991-2000 and 232nd in 2001-2014.

As of 2015, Igbeti had a built-up area of 2.84 square kilometers, and a population of 97026 people.

These are some other cities with approximately the same population: