Kaidō, however, do not include San'yōdō, San'indō, Nankaidō and Saikaidō, which were part of the even more ancient system of Yamato government called Gokishichidō.
Later, Edo was the reference, and even today Japan reckons directions and measures distances along its highways from Nihonbashi in Chūō, Tokyo.
The five main kaidō from Nihonbashi in Edo were: At various times, the government established post stations (shukuba) along the roads.
Daimyō, making the required sankin-kōtai trip between their han and Edo, also traveled along the kaidō and stayed at post stations.
The Bunraku play Kanadehon Chūshingura, the fictionalized account of the true story of the Forty-seven Ronin, has several scenes set along various kaidō.