Behind this lies a construction plan of the early Meiji period, and there were divided opinions over which route--Tokaido or Nakasen-do Street--would be preferable for construction. Initially the government accepted the route along Nakasen-do Street and started service in some sections, but later it realized that the route along the Tokaido was better, considering the earlier plan's higher estimated costs and longer construction period, as well as the restricted transportation in mountainous areas (particularly those across the Usui-toge), so ultimately the route was shifted east of Kano (Gifu Prefecture) to the route along the Tokaido.
これは東西両京を結ぶ鉄道線を敷設するに当たって、東海道と中山道のいずれに通すかを巡って明治初期に論争があり、その結果中山道経由に一時は決定してその一部に該当する路線が開業したものの、後に碓氷峠を越える区間など山岳地域での工事の長期化・費用増、開業後の輸送量制限を考慮して、やはり東海道の方が優れているということになり、急遽岐阜（加納）以東のルートが東海道経由に変更されたことに起因している。