Street-network Sprawl in Darmstadt, Germany

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.

Darmstadt: city in Hessen, Germany

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 Darmstadt, Germany on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Darmstadt as of 2014, the overall level of street-network sprawl is 0.3, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.23, 1.33, 0.85 and 0.3. Street construction in Darmstadt increased in disconnectivity initially but has since improved. The streets constructed in 1976-1990 were the most disconnected.

Quantity of street network construction: The street network in Darmstadt spans a total of 403 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 0.23, 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 0.23, 0.3, 0.3 and 0.3. The aggregate street network in Darmstadt increased in disconnectivity initially,but the trend has turned around after 2000.

Darmstadt and Hessen do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Darmstadt peaked in 1976-1990, while the SNDi of street constructions in Hessen peaked in 1991-2000.

How do development practices in Darmstadt fare in comparison to others in Hessen? Most recently in 2001-2014, street construction in Darmstadt was the 7th-most disconnected out of the 7 cities in Hessen. Its position in the ranks since 1975 has not changed. Darmstadt ranked 7th in 1975, 6th in 1976-1990, 7th in 1991-2000 and 7th in 2001-2014.

Darmstadt and Germany do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Darmstadt peaked in 1976-1990, while the SNDi of street constructions in Germany peaked in 1991-2000.

How do development practices in Darmstadt fare in comparison to others in Germany? Most recently in 2001-2014, street construction in Darmstadt was the 81st-most disconnected out of the 87 cities in Germany. Its position in the ranks since 1975 has risen; relative to other cities in Germany, street construction in Darmstadt has become more disconnected. Darmstadt ranked 87th in 1975, 75th in 1976-1990, 77th in 1991-2000 and 81st in 2001-2014.

Darmstadt and Hessen do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Darmstadt peaked in 1991-2000, while the SNDi of street constructions in Hessen rose steadily.

To date, Darmstadt is the 7th-most disconnected out of the 7 cities in Hessen. Its position in the ranks since 1975 has not changed. Darmstadt ranked 7th in 1975, 7th in 1976-1990, 7th in 1991-2000 and 7th in 2001-2014.

Darmstadt and Germany do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Darmstadt peaked in 1991-2000, while the SNDi of street constructions in Germany rose steadily.

To date, Darmstadt is the 87th-most disconnected out of the 87 cities in Germany. Its position in the ranks since 1975 has not changed. Darmstadt ranked 87th in 1975, 87th in 1976-1990, 87th in 1991-2000 and 87th in 2001-2014.

As of 2015, Darmstadt had a built-up area of 26.05 square kilometers, and a population of 116050 people.

These are some other cities with approximately the same population: