Street-network Sprawl in Hashtgerd, 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.

Hashtgerd: city in Alborz, 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 Hashtgerd, Iran on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Hashtgerd as of 2014, the overall level of street-network sprawl is 3.34, which is highly disconnected.

Trends in street network construction: The SNDis of street construction for the respective time periods are nan, 1.91, 3.64 and 4.93. Data was not available in 1975.

Quantity of street network construction: The street network in Hashtgerd spans a total of 142 kilometers. The period with the greatest volume of street construction was 1975. These roads have an SNDi of nan, which is highly disconnected.

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 nan, 1.91, 2.69 and 3.34. Data was not available in 1975.

Hashtgerd and Alborz do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Alborz was at its lowest in 1976-1990.

How do development practices in Hashtgerd fare in comparison to others in Alborz? Most recently in 2001-2014, street construction in Hashtgerd was the 2nd-most disconnected out of the 4 cities in Alborz. Its position in the ranks since 1975 has not changed. Hashtgerd ranked 2nd in 1976-1990, 2nd in 1991-2000 and 2nd in 2001-2014. There was no ranking in 1975 due to unavailable data.

Hashtgerd and Iran do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

How do development practices in Hashtgerd fare in comparison to others in Iran? Most recently in 2001-2014, street construction in Hashtgerd was the 17th-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has risen; relative to other cities in Iran, street construction in Hashtgerd has become more disconnected. Hashtgerd ranked 71st in 1976-1990, 45th in 1991-2000 and 17th in 2001-2014. There was no ranking in 1975 due to unavailable data.

Hashtgerd and Alborz do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Alborz was at its lowest in 1976-1990.

To date, Hashtgerd is the 1st-most disconnected out of the 4 cities in Alborz. Its position in the ranks since 1975 has risen; relative to other cities in Alborz, the street network in Hashtgerd has become more disconnected. Hashtgerd ranked 2nd in 1976-1990, 2nd in 1991-2000 and 1st in 2001-2014. There was no ranking in 1975 due to unavailable data.

Hashtgerd and Iran do not follow the same trend in the disconnectivity of their aggregate street networks. There was not enough data from the city, while the SNDi of street constructions in Iran was at its lowest in 1976-1990.

To date, Hashtgerd is the 32nd-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has risen; relative to other cities in Iran, the street network in Hashtgerd has become more disconnected. Hashtgerd ranked 75th in 1976-1990, 50th in 1991-2000 and 32nd in 2001-2014. There was no ranking in 1975 due to unavailable data.

As of 2015, Hashtgerd had a built-up area of 3.74 square kilometers, and a population of 51086 people.

These are some other cities with approximately the same population: