Street-network Sprawl in Cabo Delgado, Mozambique

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.

Cabo Delgado: region in Mozambique

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 Cabo Delgado, Mozambique on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Cabo Delgado as of 2014, the overall level of street-network sprawl is 2.66, 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 2.13, 2.91, 3.85 and 3.59. Street construction in Cabo Delgado 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 Cabo Delgado spans a total of 8841 kilometers. The period with the greatest volume of street construction was 1975. These roads have an SNDi of 2.13, 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 2.13, 2.31, 2.48 and 2.66. Overall, the SNDi of the aggregate street network has risen: the street network in Cabo Delgado has become more disconnected.

The level of street-network sprawl in new development in Cabo Delgado peaked in 1991-2000. To get a sense of how street development has changed in Cabo Delgado, we can consider three of its most populous cities: Montepuez, Chiure-Sede and Mocímboa da Praia. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Montepuez rose steadily. The level of street-network sprawl in new development in Chiure-Sede followed a zig-zag trend. The level of street-network sprawl in new development in Mocímboa da Praia followed a zig-zag trend with an overall increase.

How do development practices in Cabo Delgado fare in comparison to others in Mozambique? Most recently in 2001-2014, street construction in Cabo Delgado was the 3rd-most disconnected out of the 10 regions in Mozambique. Its position in the ranks since 1975 has risen; relative to other regions in Mozambique, street construction in Cabo Delgado has become more disconnected. Cabo Delgado ranked 5th in 1975, 6th in 1976-1990, 1st in 1991-2000 and 3rd in 2001-2014.

As of 2014, the city with the most disconnected street network in Cabo Delgado is Mocímboa da Praia with an SNDi of 3.25, which is in the 40th to 60th percentile of disconnectedness. Conversely, the most connected city is Chiure-Sede with an SNDi of -2.89, which is very well-connected. See trends for these cities: Chiure-Sede, Mocímboa da Praia

The level of street-network sprawl in the aggregate network in Cabo Delgado rose steadily. To get a sense of how the aggregate street network has changed in Cabo Delgado, we can consider three of its most populous cities: Montepuez, Chiure-Sede and Mocímboa da Praia. Out of the three cities, Chiure-Sede and Mocímboa da Praia do not follow the same trend as the region. The level of street-network sprawl in the aggregate network in Chiure-Sede rose steadily. The level of street-network sprawl in the aggregate network in Mocímboa da Praia followed a zig-zag trend with an overall increase.

To date, Cabo Delgado is the 7th-most disconnected out of the 10 regions in Mozambique. Its position in the ranks since 1975 has fallen; relative to other regions in Mozambique, the street network in Cabo Delgado has become more connected. Cabo Delgado ranked 5th in 1975, 5th in 1976-1990, 5th in 1991-2000 and 7th in 2001-2014.