Street-network Sprawl in Al Jizah, Egypt

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.

Al Jizah: region in Egypt

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 Al Jizah, Egypt on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Al Jizah as of 2014, the overall level of street-network sprawl is 3.15, 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 2.5, 3.26, 3.87 and 3.68. Street construction in Al Jizah 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 Al Jizah spans a total of 9913 kilometers. The period with the greatest volume of street construction was 1975. These roads have an SNDi of 2.5, 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 2.5, 2.78, 2.97 and 3.15. Overall, the SNDi of the aggregate street network has risen: the street network in Al Jizah has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.29 points, but between 1991-2000 and 2001-2014, it rose by just 0.17.

The level of street-network sprawl in new development in Al Jizah peaked in 1991-2000. To get a sense of how street development has changed in Al Jizah, we can consider three of its most populous cities: Cairo, Minyat Sultan and 6th of October. None of the most populous cities follow the same trend as the region. The level of street-network sprawl in new development in Cairo followed a zig-zag trend with an overall increase. The level of street-network sprawl in new development in Minyat Sultan followed a zig-zag trend. The level of street-network sprawl in new development in 6th of October followed a zig-zag trend.

How do development practices in Al Jizah fare in comparison to others in Egypt? Most recently in 2001-2014, street construction in Al Jizah was the 19th-most disconnected out of the 25 regions in Egypt. Its position in the ranks since 1975 has fallen; relative to other regions in Egypt, street construction in Al Jizah has become more connected. Al Jizah ranked 16th in 1975, 14th in 1976-1990, 18th in 1991-2000 and 19th in 2001-2014.

As of 2014, the city with the most disconnected street network in Al Jizah is Al-Qobabat with an SNDi of 5.96, which is highly disconnected. Conversely, the most connected city is Cairo with an SNDi of 2.12, which is relatively well-connected. See trends for these cities: Cairo, Al-Qobabat

The level of street-network sprawl in the aggregate network in Al Jizah rose steadily. To get a sense of how the aggregate street network has changed in Al Jizah, we can consider three of its most populous cities: Cairo, Minyat Sultan and 6th of October. Out of the three cities, Minyat Sultan and 6th of October do not follow the same trend as the region. The level of street-network sprawl in the aggregate network in Minyat Sultan rose steadily. The level of street-network sprawl in the aggregate network in 6th of October followed a zig-zag trend.

To date, Al Jizah is the 18th-most disconnected out of the 25 regions in Egypt. Its position in the ranks since 1975 has fallen; relative to other regions in Egypt, the street network in Al Jizah has become more connected. Al Jizah ranked 16th in 1975, 17th in 1976-1990, 17th in 1991-2000 and 18th in 2001-2014.