Street-network Sprawl in Benue, 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.

Benue: region in 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 Benue, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Benue as of 2014, the overall level of street-network sprawl is 3.24, 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 1.8, 2.9, 4.76 and 3.56. Street construction in Benue increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Benue spans a total of 7344 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 3.56, 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 1.8, 2.6, 2.72 and 3.24. Overall, the SNDi of the aggregate street network has risen: the street network in Benue has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.79 points, but between 1991-2000 and 2001-2014, it rose by just 0.52.

The level of street-network sprawl in new development in Benue peaked in 1991-2000. To get a sense of how street development has changed in Benue, we can consider three of its most populous cities: Gboko, Makurdi and Otukpo. Out of the three cities, Makurdi does not follow the same trend as the region. The level of street-network sprawl in new development in Makurdi rose steadily.

How do development practices in Benue fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Benue was the 19th-most disconnected out of the 37 regions in Nigeria. Its position in the ranks since 1975 has risen; relative to other regions in Nigeria, street construction in Benue has become more disconnected. Benue ranked 26th in 1975, 20th in 1976-1990, 9th in 1991-2000 and 19th in 2001-2014.

As of 2014, the city with the most disconnected street network in Benue is Adum East with an SNDi of 4.8, which is highly disconnected. Conversely, the most connected city is Ugbokolo with an SNDi of -1.13, which is very well-connected. See trends for these cities: Ugbokolo, Adum East

The level of street-network sprawl in the aggregate network in Benue rose steadily. To get a sense of how the aggregate street network has changed in Benue, we can consider three of its most populous cities: Gboko, Makurdi and Otukpo. Disconnectivity in the most populous cities in Benue follow the same region trend.

To date, Benue is the 19th-most disconnected out of the 37 regions in Nigeria. Its position in the ranks since 1975 has risen; relative to other regions in Nigeria, the street network in Benue has become more disconnected. Benue ranked 26th in 1975, 21st in 1976-1990, 21st in 1991-2000 and 19th in 2001-2014.