Japan National Route 20

Japanese National Route 20 connects central Tokyo with Shiojiri in Nagano Prefecture, essentially following the old Koshu Kaido, one of Edo Japan's five great highways. The Koshu Kaido once ran from Edo to Shimosuwa, serving daimyo processions and postal traffic, and some post towns along the route still preserve historic streetscapes. Today Route 20 is a continuous asphalt corridor mostly used by commuters and freight.