Street-network Sprawl in Isfara, Tajikistan

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.

Isfara: city in Leninabad, Tajikistan

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 Isfara, Tajikistan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Isfara as of 2014, the overall level of street-network sprawl is 2.75, 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 3.55, 2.88, 1.55 and 2.16. The disconnectivity of new streets constructed in Isfara fell, then rose. In 1991-2000, new street layouts were the most connected.

Quantity of street network construction: The street network in Isfara spans a total of 142 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 2.88, 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 3.55, 2.96, 2.91 and 2.75. Overall, the SNDi of the aggregate street network has fallen: the street network in Isfara has become more connected.

Isfara and Leninabad do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Isfara was at its lowest in 1991-2000, while the SNDi of street constructions in Leninabad followed a zig-zag trend with an overall decrease.

How do development practices in Isfara fare in comparison to others in Leninabad? Most recently in 2001-2014, street construction in Isfara was the 4th-most disconnected out of the 5 cities in Leninabad. Its position in the ranks since 1975 has fallen; relative to other cities in Leninabad, street construction in Isfara has become more connected. Isfara ranked 2nd in 1975, 2nd in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014.

Isfara and Tajikistan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Isfara was at its lowest in 1991-2000, while the SNDi of street constructions in Tajikistan was at its lowest in 1976-1990.

How do development practices in Isfara fare in comparison to others in Tajikistan? Most recently in 2001-2014, street construction in Isfara was the 11th-most disconnected out of the 14 cities in Tajikistan. Its position in the ranks since 1975 has fallen; relative to other cities in Tajikistan, street construction in Isfara has become more connected. Isfara ranked 5th in 1975, 7th in 1976-1990, 11th in 1991-2000 and 11th in 2001-2014.

Isfara and Leninabad follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these fell steadily.

To date, Isfara is the 3rd-most disconnected out of the 5 cities in Leninabad. Its position in the ranks since 1975 has fallen; relative to other cities in Leninabad, the street network in Isfara has become more connected. Isfara ranked 2nd in 1975, 2nd in 1976-1990, 3rd in 1991-2000 and 3rd in 2001-2014.

Isfara and Tajikistan do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Isfara fell steadily, while the SNDi of street constructions in Tajikistan was at its lowest in 1991-2000.

To date, Isfara is the 10th-most disconnected out of the 14 cities in Tajikistan. Its position in the ranks since 1975 has fallen; relative to other cities in Tajikistan, the street network in Isfara has become more connected. Isfara ranked 5th in 1975, 6th in 1976-1990, 8th in 1991-2000 and 10th in 2001-2014.

As of 2015, Isfara had a built-up area of 9.6 square kilometers, and a population of 60615 people.

These are some other cities with approximately the same population: