Street-network Sprawl in Tangier, Morocco

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.

Tangier: city in Tanger - Tétouan, Morocco

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 Tangier, Morocco on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Tangier as of 2014, the overall level of street-network sprawl is 1.04, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.6, 1.01, 1.27 and 2.46. In each period, new street development in Tangier steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Tangier spans a total of 1313 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 0.6, 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 0.6, 0.66, 0.72 and 1.04. Overall, the SNDi of the aggregate street network has risen: the street network in Tangier has become more disconnected.

Tangier and Tanger - Tétouan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Tangier rose steadily, while the SNDi of street constructions in Tanger - Tétouan followed a zig-zag trend with an overall increase.

How do development practices in Tangier fare in comparison to others in Tanger - Tétouan? Most recently in 2001-2014, street construction in Tangier was the 5th-most disconnected out of the 6 cities in Tanger - Tétouan. Its position in the ranks since 1975 has risen; relative to other cities in Tanger - Tétouan, street construction in Tangier has become more disconnected. Tangier ranked 6th in 1975, 5th in 1976-1990, 6th in 1991-2000 and 5th in 2001-2014.

Tangier and Morocco 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 Tangier fare in comparison to others in Morocco? Most recently in 2001-2014, street construction in Tangier was the 18th-most disconnected out of the 61 cities in Morocco. Its position in the ranks since 1975 has risen; relative to other cities in Morocco, street construction in Tangier has become more disconnected. Tangier ranked 44th in 1975, 35th in 1976-1990, 32nd in 1991-2000 and 18th in 2001-2014.

Tangier and Tanger - Tétouan follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Tangier is the 6th-most disconnected out of the 6 cities in Tanger - Tétouan. Its position in the ranks since 1975 has not changed. Tangier ranked 6th in 1975, 6th in 1976-1990, 6th in 1991-2000 and 6th in 2001-2014.

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

To date, Tangier is the 41st-most disconnected out of the 61 cities in Morocco. Its position in the ranks since 1975 has risen; relative to other cities in Morocco, the street network in Tangier has become more disconnected. Tangier ranked 44th in 1975, 48th in 1976-1990, 46th in 1991-2000 and 41st in 2001-2014.

As of 2015, Tangier had a built-up area of 49.17 square kilometers, and a population of 976954 people.

These are some other cities with approximately the same population: