The pass, however, was a rough and narrow road with a series of steep slopes and sharp curves, so a bypass project to extend the road by 2.3 kilometers (including the 953-meter-extension with Sugasaka Minami Tunnel) was started in 1995 (Sugasaka Bypass). |
しかし道幅が狭く、急勾配、急カーブが連続する悪路であり、1995年(平成7年)より菅坂南トンネル(延長953m)を含む延長2.3kmのバイパス道路事業(菅坂バイパス)を進めた。 |