Street-network Sprawl in Bellingham, United States

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.

Bellingham: city in Washington, United States

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 Bellingham, United States on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Bellingham as of 2014, the overall level of street-network sprawl is 2.15, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.88, 3.68, 5.5 and 5.31. Street construction in Bellingham 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 Bellingham spans a total of 483 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 0.88, 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 0.88, 1.92, 2.07 and 2.15. Overall, the SNDi of the aggregate street network has risen: the street network in Bellingham has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 1.03 points, but between 1991-2000 and 2001-2014, it rose by just 0.07.

Bellingham and Washington 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 Bellingham fare in comparison to others in Washington? Most recently in 2001-2014, street construction in Bellingham was the 3rd-most disconnected out of the 6 cities in Washington. Its position in the ranks since 1975 has risen; relative to other cities in Washington, street construction in Bellingham has become more disconnected. Bellingham ranked 6th in 1975, 5th in 1976-1990, 4th in 1991-2000 and 3rd in 2001-2014.

Bellingham and United States 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 Bellingham fare in comparison to others in United States? Most recently in 2001-2014, street construction in Bellingham was the 143rd-most disconnected out of the 315 cities in United States. Its position in the ranks since 1975 has risen; relative to other cities in United States, street construction in Bellingham has become more disconnected. Bellingham ranked 304th in 1975, 222nd in 1976-1990, 152nd in 1991-2000 and 143rd in 2001-2014.

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

To date, Bellingham is the 5th-most disconnected out of the 6 cities in Washington. Its position in the ranks since 1975 has risen; relative to other cities in Washington, the street network in Bellingham has become more disconnected. Bellingham ranked 6th in 1975, 5th in 1976-1990, 5th in 1991-2000 and 5th in 2001-2014.

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

To date, Bellingham is the 258th-most disconnected out of the 315 cities in United States. Its position in the ranks since 1975 has risen; relative to other cities in United States, the street network in Bellingham has become more disconnected. Bellingham ranked 304th in 1975, 260th in 1976-1990, 257th in 1991-2000 and 258th in 2001-2014.

As of 2015, Bellingham had a built-up area of 28.01 square kilometers, and a population of 72912 people.

These are some other cities with approximately the same population: