The level of street-network sprawl in new development in Yamaguchi followed a zig-zag trend with an overall increase. To get a sense of how street development has changed in Yamaguchi, we can consider three of its most populous cities: Shunan, Ube and Iwakuni. Out of the three cities, Ube does not follow the same trend as the region. The level of street-network sprawl in new development in Ube rose steadily.

How do development practices in Yamaguchi fare in comparison to others in Japan? Most recently in 2006-2020, street construction in Yamaguchi was the 42nd-most disconnected out of the 44 regions in Japan. Its position in the ranks since 1975 has risen; relative to other regions in Japan, street construction in Yamaguchi has become more disconnected. Yamaguchi ranked 43rd in 1975, 42nd in 1976-1990, 44th in 1991-2005 and 42nd in 2006-2020.

As of 2020, the city with the most disconnected street network in Yamaguchi is Yamaguchi with an SNDi of 3.45, which is relatively sprawly. Conversely, the most connected city is Shunan with an SNDi of 2.75, which is relatively well-connected. See trends for these cities: Shunan, Yamaguchi

The level of street-network sprawl in the aggregate network in Yamaguchi rose steadily. To get a sense of how the aggregate street network has changed in Yamaguchi, we can consider three of its most populous cities: Shunan, Ube and Iwakuni. Disconnectivity in the most populous cities in Yamaguchi follow the same region trend.

To date, Yamaguchi is the 43rd-most disconnected out of the 44 regions in Japan. Its position in the ranks since 1975 has not changed. Yamaguchi ranked 43rd in 1975, 42nd in 1976-1990, 43rd in 1991-2005 and 43rd in 2006-2020.