Street-network Sprawl in Västerås, Sweden

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.

Västerås: city in Västmanland, Sweden

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 Västerås, Sweden on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Västerås as of 2014, the overall level of street-network sprawl is 1.1, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.08, 1.28, 4.49 and 0.8. Street construction in Västerås 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 Västerås spans a total of 384 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.08, 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 1.08, 1.09, 1.1 and 1.1. The aggregate street network in Västerås increased in disconnectivity initially,but the trend has turned around after 2000.

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

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

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

How do development practices in Västerås fare in comparison to others in Sweden? Most recently in 2001-2014, street construction in Västerås was the 9th-most disconnected out of the 12 cities in Sweden. Its position in the ranks since 1975 has fallen; relative to other cities in Sweden, street construction in Västerås has become more connected. Västerås ranked 5th in 1975, 7th in 1976-1990, 1st in 1991-2000 and 9th in 2001-2014.

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

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

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

To date, Västerås is the 5th-most disconnected out of the 12 cities in Sweden. Its position in the ranks since 1975 has not changed. Västerås ranked 5th in 1975, 5th in 1976-1990, 5th in 1991-2000 and 5th in 2001-2014.

As of 2015, Västerås had a built-up area of 19.83 square kilometers, and a population of 87593 people.

These are some other cities with approximately the same population: