Street-network Sprawl in Athens, Greece

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.

Athens: city in Attica, Greece

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 Athens, Greece on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Athens as of 2014, the overall level of street-network sprawl is 0.05, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are -0.09, 1.21, 1.99 and 1.38. Street construction in Athens increased in disconnectivity initially but has since improved. The streets constructed in 1991-2000 were the most disconnected.

Quantity of street network construction: The street network in Athens spans a total of 8401 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of -0.09, which is very 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 -0.09, 0.03, 0.04 and 0.05. Overall, the SNDi of the aggregate street network has risen: the street network in Athens has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.12 points, but between 1991-2000 and 2001-2014, it rose by just 0.01.

Athens and Attica do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Athens peaked in 1991-2000, while the SNDi of street constructions in Attica rose steadily.

How do development practices in Athens fare in comparison to others in Attica? Most recently in 2001-2014, street construction in Athens was the 1st-most disconnected out of the 1 cities in Attica. Its position in the ranks since 1975 has not changed. Athens ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Athens and Greece do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Athens peaked in 1991-2000, while the SNDi of street constructions in Greece rose steadily.

How do development practices in Athens fare in comparison to others in Greece? Most recently in 2001-2014, street construction in Athens was the 7th-most disconnected out of the 10 cities in Greece. Its position in the ranks since 1975 has risen; relative to other cities in Greece, street construction in Athens has become more disconnected. Athens ranked 9th in 1975, 9th in 1976-1990, 5th in 1991-2000 and 7th in 2001-2014.

Athens and Attica follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Athens is the 1st-most disconnected out of the 1 cities in Attica. Its position in the ranks since 1975 has not changed. Athens ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Athens and Greece follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Athens is the 10th-most disconnected out of the 10 cities in Greece. Its position in the ranks since 1975 has fallen; relative to other cities in Greece, the street network in Athens has become more connected. Athens ranked 9th in 1975, 10th in 1976-1990, 10th in 1991-2000 and 10th in 2001-2014.

As of 2015, Athens had a built-up area of 326.12 square kilometers, and a population of 3315199 people.

These are some other cities with approximately the same population: