Street-network Sprawl in Hamamatsu, 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.

Hamamatsu: city in Shizuoka, 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 Hamamatsu, Japan on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Hamamatsu as of 2014, the overall level of street-network sprawl is 0.37, which is very well-connected.

Trends in street network construction: The SNDis of street construction for the respective time periods are 0.34, 0.72, 4.68 and 1.47. Street construction in Hamamatsu 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 Hamamatsu spans a total of 5702 kilometers. It is dominated by roads constructed prior to 1975. These roads have an SNDi of 0.34, which is very 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 0.34, 0.36, 0.36 and 0.37. Overall, the SNDi of the aggregate street network has risen: the street network in Hamamatsu has become more disconnected. This increase has slowed: between 1975 and 1976-1990, SNDi rose by 0.02 points, but between 1991-2000 and 2001-2014, it rose by just 0.0.

Hamamatsu and Shizuoka 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 Hamamatsu fare in comparison to others in Shizuoka? Most recently in 2001-2014, street construction in Hamamatsu was the 4th-most disconnected out of the 5 cities in Shizuoka. Its position in the ranks since 1975 has risen; relative to other cities in Shizuoka, street construction in Hamamatsu has become more disconnected. Hamamatsu ranked 5th in 1975, 5th in 1976-1990, 2nd in 1991-2000 and 4th in 2001-2014.

Hamamatsu and Japan 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 Hamamatsu fare in comparison to others in Japan? Most recently in 2001-2014, street construction in Hamamatsu was the 59th-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 Hamamatsu has become more disconnected. Hamamatsu ranked 104th in 1975, 86th in 1976-1990, 12th in 1991-2000 and 59th in 2001-2014.

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

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

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

To date, Hamamatsu is the 105th-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 Hamamatsu has become more connected. Hamamatsu ranked 104th in 1975, 105th in 1976-1990, 105th in 1991-2000 and 105th in 2001-2014.

As of 2015, Hamamatsu had a built-up area of 214.83 square kilometers, and a population of 718870 people.

These are some other cities with approximately the same population: