Street-network Sprawl in Tarsus, Turkey

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.

Tarsus: city in Mersin, Turkey

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 Tarsus, Turkey on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Tarsus as of 2014, the overall level of street-network sprawl is 0.81, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.89, 0.72, 0.85 and 1.36. The disconnectivity of new streets constructed in Tarsus fell, then rose. In 1976-1990, new street layouts were the most connected.

Quantity of street network construction: The street network in Tarsus spans a total of 647 kilometers. It is dominated by roads constructed in 1976-1990. These roads have an SNDi of 0.72, 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 0.89, 0.77, 0.77 and 0.81. The SNDi of the aggregate street network in fell at first, but Tarsus has worsened in disconnectivity since 1990.

Tarsus and Mersin 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 Tarsus fare in comparison to others in Mersin? Most recently in 2001-2014, street construction in Tarsus was the 2nd-most disconnected out of the 2 cities in Mersin. Its position in the ranks since 1975 has not changed. Tarsus ranked 2nd in 1975, 1st in 1976-1990, 2nd in 1991-2000 and 2nd in 2001-2014.

Tarsus and Turkey do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Tarsus was at its lowest in 1976-1990, while the SNDi of street constructions in Turkey rose steadily.

How do development practices in Tarsus fare in comparison to others in Turkey? Most recently in 2001-2014, street construction in Tarsus was the 89th-most disconnected out of the 134 cities in Turkey. Its position in the ranks since 1975 has fallen; relative to other cities in Turkey, street construction in Tarsus has become more connected. Tarsus ranked 64th in 1975, 84th in 1976-1990, 88th in 1991-2000 and 89th in 2001-2014.

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

Tarsus and Turkey do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Tarsus was at its lowest in 1976-1990, while the SNDi of street constructions in Turkey rose steadily.

To date, Tarsus is the 83rd-most disconnected out of the 134 cities in Turkey. Its position in the ranks since 1975 has fallen; relative to other cities in Turkey, the street network in Tarsus has become more connected. Tarsus ranked 64th in 1975, 78th in 1976-1990, 80th in 1991-2000 and 83rd in 2001-2014.

As of 2015, Tarsus had a built-up area of 18.48 square kilometers, and a population of 159692 people.

These are some other cities with approximately the same population: