Street-network Sprawl in Akita, Japan


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.

Akita: city in Japan

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 Akita, Japan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Akita as of 2014, the overall level of street-network sprawl is 1.81, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.8, nan, 2.55 and 2.22. Data was not available in 1976-1990.

Quantity of street network construction: The street network in Akita spans a total of 1258 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, 1.8, 1.81 and 1.81. Overall, the SNDi of the aggregate street network has risen: the street network in Akita has become more disconnected.

Akita and Akita do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Akita peaked in 1991-2000.

How do development practices in Akita fare in comparison to others in Akita? Most recently in 2001-2014, street construction in Akita was the 1st-most disconnected out of the 1 cities in Akita. Its position in the ranks since 1975 has not changed. Akita ranked 1st in 1975, 1st in 1991-2000 and 1st in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.

Akita and Japan do not follow the same trend in the disconnectivity of their street network constructions. There was not enough data from the city, while the SNDi of street constructions in Japan peaked in 1991-2000.

How do development practices in Akita fare in comparison to others in Japan? Most recently in 2001-2014, street construction in Akita was the 40th-most disconnected out of the 109 cities in Japan. Its position in the ranks since 1975 has risen; relative to other cities in Japan, street construction in Akita has become more disconnected. Akita ranked 33rd in 1975, 47th in 1991-2000 and 40th in 2001-2014. There was no ranking in 1976-1990 due to unavailable data.

Akita and Akita do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Akita rose steadily, while the SNDi of street constructions in Akita rose steadily.

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

Akita and Japan do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Akita rose steadily, while the SNDi of street constructions in Japan rose steadily.

To date, Akita is the 39th-most disconnected out of the 109 cities in Japan. Its position in the ranks since 1975 has fallen; relative to other cities in Japan, the street network in Akita has become more connected. Akita ranked 33rd in 1975, 39th in 1976-1990, 39th in 1991-2000 and 39th in 2001-2014.

As of 2015, Akita had a built-up area of 51.11 square kilometers, and a population of 212354 people.

These are some other cities with approximately the same population: