Street-network Sprawl in Bergamo, Italy

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.

Bergamo: city in Lombardia, Italy

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 Bergamo, Italy on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Bergamo as of 2014, the overall level of street-network sprawl is 3.03, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 2.56, 4.01, 4.79 and 4.46. Street construction in Bergamo 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 Bergamo spans a total of 1440 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 2.56, which is in the 40th to 60th percentile of disconnectedness.

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 2.56, 2.99, 3.03 and 3.03. Overall, the SNDi of the aggregate street network has risen: the street network in Bergamo has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.43 points, but between 1991-2000 and 2001-2014, it rose by just 0.0.

Bergamo and Lombardia follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these peaked in 1991-2000.

How do development practices in Bergamo fare in comparison to others in Lombardia? Most recently in 2001-2014, street construction in Bergamo was the 3rd-most disconnected out of the 11 cities in Lombardia. Its position in the ranks since 1975 has risen; relative to other cities in Lombardia, street construction in Bergamo has become more disconnected. Bergamo ranked 4th in 1975, 5th in 1976-1990, 4th in 1991-2000 and 3rd in 2001-2014.

Bergamo and Italy follow the same trend in the disconnectivity of their street network constructions. The SNDi for both of these peaked in 1991-2000.

How do development practices in Bergamo fare in comparison to others in Italy? Most recently in 2001-2014, street construction in Bergamo was the 29th-most disconnected out of the 91 cities in Italy. Its position in the ranks since 1975 has fallen; relative to other cities in Italy, street construction in Bergamo has become more connected. Bergamo ranked 16th in 1975, 26th in 1976-1990, 21st in 1991-2000 and 29th in 2001-2014.

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

To date, Bergamo is the 3rd-most disconnected out of the 11 cities in Lombardia. Its position in the ranks since 1975 has risen; relative to other cities in Lombardia, the street network in Bergamo has become more disconnected. Bergamo ranked 4th in 1975, 3rd in 1976-1990, 3rd in 1991-2000 and 3rd in 2001-2014.

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

To date, Bergamo is the 15th-most disconnected out of the 91 cities in Italy. Its position in the ranks since 1975 has risen; relative to other cities in Italy, the street network in Bergamo has become more disconnected. Bergamo ranked 16th in 1975, 15th in 1976-1990, 15th in 1991-2000 and 15th in 2001-2014.

As of 2015, Bergamo had a built-up area of 73.57 square kilometers, and a population of 353586 people.

These are some other cities with approximately the same population: