Seven Roads of Japan

After the Reformation of the Taika Era (645) and the establishment of an elaborate central government system with administrative and judicial institutions modeled after the Tang Dynasty in China, a road network covering all of Honshu, Shikoku, and Kyushu was established. This public road network system on a nationwide scale is the system of Seven Roads, and it included the famous Tokaido, Tosando, Hokurikudo, San-indo, San-yodo, Nankaido, and Saikaido.
They were built by adapting to and overcoming the restrictions of Japan's complex topography, and became the prototype of highways and roads in later periods. Arterial railways constructed after the Meiji Era and the expressways that have successively opened since 1964 roughly follow the same routes taken by these roads. In short, the Seven Roads established during this age are the backbone of today's traffic routes in Japan

From the History of Japanese Roads, courtesy of the Road Bureau of Japan's Ministry of Land, Infrastructure and Transport.

The image of Shinagawa (the first stop on the Tokaido) is from Ando Hiroshige's "Fifty-Three Stations of the Tokaido" (first, or Hoeido, series) which can be found here at the superb Woodblock Prints of Ando Hiroshige website.