Street-network Sprawl in Zwolle, Netherlands

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.

Zwolle: city in Overijssel, Netherlands

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 Zwolle, Netherlands on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Zwolle as of 2014, the overall level of street-network sprawl is 1.85, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.8, 2.12, 1.3 and 1.77. Disconnectivity in street construction in Zwolle follows a zig-zag trend. In 1991-2000, street construction was most disconnected, while construction was most connected in 1976-1990.

Quantity of street network construction: The street network in Zwolle spans a total of 573 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.8, 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 1.8, 1.94, 1.86 and 1.85. The aggregate street network in Zwolle increased in disconnectivity initially,but the trend has turned around after 1990.

Zwolle and Overijssel follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these followed a zig-zag trend with an overall decrease.

How do development practices in Zwolle fare in comparison to others in Overijssel? Most recently in 2001-2014, street construction in Zwolle was the 4th-most disconnected out of the 5 cities in Overijssel. Its position in the ranks since 1975 has fallen; relative to other cities in Overijssel, street construction in Zwolle has become more connected. Zwolle ranked 1st in 1975, 1st in 1976-1990, 4th in 1991-2000 and 4th in 2001-2014.

Zwolle and Netherlands do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Zwolle followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Netherlands rose steadily.

How do development practices in Zwolle fare in comparison to others in Netherlands? Most recently in 2001-2014, street construction in Zwolle was the 24th-most disconnected out of the 37 cities in Netherlands. Its position in the ranks since 1975 has fallen; relative to other cities in Netherlands, street construction in Zwolle has become more connected. Zwolle ranked 9th in 1975, 11th in 1976-1990, 30th in 1991-2000 and 24th in 2001-2014.

Zwolle and Overijssel do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Zwolle peaked in 1976-1990, while the SNDi of street constructions in Overijssel rose steadily.

To date, Zwolle is the 1st-most disconnected out of the 5 cities in Overijssel. Its position in the ranks since 1975 has not changed. Zwolle ranked 1st in 1975, 1st in 1976-1990, 1st in 1991-2000 and 1st in 2001-2014.

Zwolle and Netherlands do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Zwolle peaked in 1976-1990, while the SNDi of street constructions in Netherlands rose steadily.

To date, Zwolle is the 9th-most disconnected out of the 37 cities in Netherlands. Its position in the ranks since 1975 has not changed. Zwolle ranked 9th in 1975, 8th in 1976-1990, 9th in 1991-2000 and 9th in 2001-2014.

As of 2015, Zwolle had a built-up area of 21.96 square kilometers, and a population of 101499 people.

These are some other cities with approximately the same population:

For some related information about population, urban extent and density, and roads, visit the Atlas of Urban Expansion.