Prefectural road
A prefectural road (都道府県道 todōfukendō) in Japan is a road numbered by the prefecture, independent of other prefectures.
These roads are marked with a blue hexagon, with the number centered. Most usually end at another prefectural road, or national route, or occasionally at or very close to a Japan Railway station.
If a prefectural road does cross into another prefecture, even if for a few hundred feet, its number is not reused by the prefecture it crosses into. Numbers are used only once in each prefecture, regardless of where the road begins or ends.
Some prefectural roads will also at times run for a short distance concurrent with a national route, but it is more common to see this with other prefectural roads.
Numbers used for national routes that run through a prefecture are often duplicated by prefectural routes but a national route and a prefectural route bearing the same number rarely if ever meet or cross each other.