- Other Names: 甲州道中 (Kôshû dôchû)
- Japanese: 甲州街道 (Kôshû kaidô)
The Kôshû-kaidô or Kôshû-dôchû was a major Edo period highway which ran from Nihonbashi in Edo to Lake Suwa 諏訪湖, where it joined the Nakasendô, passing through Kai province, which was also called Kôshû. The original route went north of Mt. Takao through the Kobotoke Pass 小仏峠, parallel to the route today of Tokyo's JR Chûô train line.
Kai province had come under Tokugawa Ieyasu's control in 1582, and during the Edo period the Kôshû Highway was considered a militarily sensitive escape route. Only a few daimyo were allowed to use it; most had to take the longer route of the Nakasendô highway. While the Tôkaidô highway typically saw nearly 150 sankin kôtai entourages annually, the Kôshû kaidô was typically used by only three each year. The forty-five post-stations along the highway had a total of 41 honjin and 44 waki-honjin between them.
There was a barrier checkpoint at or near the Kobotoke Pass, originally called the Fujimi ("Mt. Fuji-viewing") barrier. Early in the Edo period it was moved a little bit east of the pass, to a site known as Komakino 駒木野. From 1623 four guards were stationed there. A permit was necessary to use the road.
The 45 stations of the Kôshû-kaidô were roughly 4.2 km away from one another; in 1843, each station had an average of 11 hatagoya and 779 residents.
- Miyamoto Tsuneichi 宮本常一, Daimyô no tabi 大名の旅, Tokyo: Shakai shisôsha (1968), 57.
- Gallery labels, Futagawa-juku honjin shiryôkan.
- Constantine Vaporis, "Linking the Realm: The Gokaidô Highway Network in Early Modern Japan," in Susan Alcock et al (eds.), Highways Byways and Road Systems in the Pre-Modern World, Wiley-Blackwell (2012), 90-105.