Street-network Sprawl in Saveh, Iran

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.

Saveh: city in Markazi, Iran

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 Saveh, Iran on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Saveh as of 2014, the overall level of street-network sprawl is 3.26, 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 3.77, 2.44, 6.47 and 2.93. Disconnectivity in street construction in Saveh follows a zig-zag trend. In 1976-1990, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Saveh spans a total of 407 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.44, 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 3.77, 2.47, 3.38 and 3.26. Disconnectivity in Saveh's street network follows a zig-zag trend. In 1976-1990, the city was most disconnected; while it was most connected in 1975.

Saveh and Markazi 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 Saveh fare in comparison to others in Markazi? Most recently in 2001-2014, street construction in Saveh was the 1st-most disconnected out of the 3 cities in Markazi. Its position in the ranks since 1975 has not changed. Saveh ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Saveh and Iran do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Saveh followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

How do development practices in Saveh fare in comparison to others in Iran? Most recently in 2001-2014, street construction in Saveh was the 87th-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has fallen; relative to other cities in Iran, street construction in Saveh has become more connected. Saveh ranked 33rd in 1975, 43rd in 1976-1990, 9th in 1991-2000 and 87th in 2001-2014.

Saveh and Markazi do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Saveh followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Markazi was at its lowest in 1976-1990.

To date, Saveh is the 1st-most disconnected out of the 3 cities in Markazi. Its position in the ranks since 1975 has not changed. Saveh ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Saveh and Iran do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Saveh followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

To date, Saveh is the 35th-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has fallen; relative to other cities in Iran, the street network in Saveh has become more connected. Saveh ranked 33rd in 1975, 50th in 1976-1990, 26th in 1991-2000 and 35th in 2001-2014.

As of 2015, Saveh had a built-up area of 11.19 square kilometers, and a population of 168649 people.

These are some other cities with approximately the same population: