Street-network Sprawl in Torbate Heydariye, 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.

Torbate Heydariye: city in Razavi Khorasan, 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 Torbate Heydariye, Iran on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Torbate Heydariye as of 2014, the overall level of street-network sprawl is 1.16, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.3, 0.71, 1.57 and 1.32. Disconnectivity in street construction in Torbate Heydariye 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 Torbate Heydariye spans a total of 318 kilometers. It is dominated by roads constructed in 2001-2014. These roads have an SNDi of 1.32, 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 1.3, 0.87, 0.98 and 1.16. The SNDi of the aggregate street network in fell at first, but Torbate Heydariye has worsened in disconnectivity since 1990.

Torbate Heydariye and Razavi Khorasan 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 increase.

How do development practices in Torbate Heydariye fare in comparison to others in Razavi Khorasan? Most recently in 2001-2014, street construction in Torbate Heydariye was the 10th-most disconnected out of the 14 cities in Razavi Khorasan. Its position in the ranks since 1975 has fallen; relative to other cities in Razavi Khorasan, street construction in Torbate Heydariye has become more connected. Torbate Heydariye ranked 9th in 1975, 11th in 1976-1990, 10th in 1991-2000 and 10th in 2001-2014.

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

How do development practices in Torbate Heydariye fare in comparison to others in Iran? Most recently in 2001-2014, street construction in Torbate Heydariye was the 158th-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 Torbate Heydariye has become more connected. Torbate Heydariye ranked 101st in 1975, 147th in 1976-1990, 115th in 1991-2000 and 158th in 2001-2014.

Torbate Heydariye and Razavi Khorasan follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these was at its lowest in 1976-1990.

To date, Torbate Heydariye is the 13th-most disconnected out of the 14 cities in Razavi Khorasan. Its position in the ranks since 1975 has fallen; relative to other cities in Razavi Khorasan, the street network in Torbate Heydariye has become more connected. Torbate Heydariye ranked 9th in 1975, 12th in 1976-1990, 14th in 1991-2000 and 13th in 2001-2014.

Torbate Heydariye and Iran follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these was at its lowest in 1976-1990.

To date, Torbate Heydariye is the 153rd-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 Torbate Heydariye has become more connected. Torbate Heydariye ranked 101st in 1975, 145th in 1976-1990, 150th in 1991-2000 and 153rd in 2001-2014.

As of 2015, Torbate Heydariye had a built-up area of 10.24 square kilometers, and a population of 70342 people.

These are some other cities with approximately the same population: