Street-network Sprawl in Khorramabad, 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.

Khorramabad: city in Lorestan, 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 Khorramabad, Iran on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Khorramabad as of 2014, the overall level of street-network sprawl is 2.87, 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 2.96, 1.91, 3.19 and 3.73. The disconnectivity of new streets constructed in Khorramabad fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Khorramabad spans a total of 833 kilometers. The period with the greatest volume of street construction was 1976-1990. These roads have an SNDi of 1.91, 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 2.96, 1.96, 2.45 and 2.87. The SNDi of the aggregate street network in fell at first, but Khorramabad has worsened in disconnectivity since 1990.

Khorramabad and Lorestan follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these was at its lowest in 1976-1990.

How do development practices in Khorramabad fare in comparison to others in Lorestan? Most recently in 2001-2014, street construction in Khorramabad was the 1st-most disconnected out of the 6 cities in Lorestan. Its position in the ranks since 1975 has risen; relative to other cities in Lorestan, street construction in Khorramabad has become more disconnected. Khorramabad ranked 2nd in 1975, 2nd in 1976-1990, 3rd in 1991-2000 and 1st in 2001-2014.

Khorramabad and Iran follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these was at its lowest in 1976-1990.

How do development practices in Khorramabad fare in comparison to others in Iran? Most recently in 2001-2014, street construction in Khorramabad was the 50th-most disconnected out of the 181 cities in Iran. Its position in the ranks since 1975 has not changed. Khorramabad ranked 50th in 1975, 72nd in 1976-1990, 53rd in 1991-2000 and 50th in 2001-2014.

Khorramabad and Lorestan 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, Khorramabad is the 1st-most disconnected out of the 6 cities in Lorestan. Its position in the ranks since 1975 has risen; relative to other cities in Lorestan, the street network in Khorramabad has become more disconnected. Khorramabad ranked 2nd in 1975, 2nd in 1976-1990, 2nd in 1991-2000 and 1st in 2001-2014.

Khorramabad 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, Khorramabad is the 47th-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 Khorramabad has become more disconnected. Khorramabad ranked 50th in 1975, 71st in 1976-1990, 55th in 1991-2000 and 47th in 2001-2014.

As of 2015, Khorramabad had a built-up area of 19.74 square kilometers, and a population of 385764 people.

These are some other cities with approximately the same population: