Street-network Sprawl in Hikone, 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.

Hikone: city in Shiga, 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 Hikone, Japan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Hikone as of 2014, the overall level of street-network sprawl is 1.73, which is relatively well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.74, 1.6, 2.79 and 0.61. Disconnectivity in street construction in Hikone follows a zig-zag trend. In 2001-2014, street construction was most disconnected, while construction was most connected in 1991-2000.

Quantity of street network construction: The street network in Hikone spans a total of 870 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 1.74, 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 1.74, 1.72, 1.73 and 1.73. Disconnectivity in Hikone's street network follows a zig-zag trend. In 1976-1990, the city was most disconnected; while it was most connected in 1975.

Hikone and Shiga do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Hikone followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Shiga peaked in 1991-2000.

How do development practices in Hikone fare in comparison to others in Shiga? Most recently in 2001-2014, street construction in Hikone was the 2nd-most disconnected out of the 2 cities in Shiga. Its position in the ranks since 1975 has not changed. Hikone ranked 2nd in 1975, 2nd in 1976-1990, 1st in 1991-2000 and 2nd in 2001-2014.

Hikone and Japan do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Hikone followed a zig-zag trend with an overall decrease, while the SNDi of street constructions in Japan peaked in 1991-2000.

How do development practices in Hikone fare in comparison to others in Japan? Most recently in 2001-2014, street construction in Hikone was the 86th-most disconnected out of the 109 cities in Japan. Its position in the ranks since 1975 has fallen; relative to other cities in Japan, street construction in Hikone has become more connected. Hikone ranked 38th in 1975, 59th in 1976-1990, 40th in 1991-2000 and 86th in 2001-2014.

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

To date, Hikone is the 2nd-most disconnected out of the 2 cities in Shiga. Its position in the ranks since 1975 has not changed. Hikone ranked 2nd in 1975, 2nd in 1976-1990, 2nd in 1991-2000 and 2nd in 2001-2014.

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

To date, Hikone is the 41st-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 Hikone has become more connected. Hikone ranked 38th in 1975, 41st in 1976-1990, 41st in 1991-2000 and 41st in 2001-2014.

As of 2015, Hikone had a built-up area of 43.96 square kilometers, and a population of 113436 people.

These are some other cities with approximately the same population: