参考(敬称略):GoogleMap https://www.google.co.jp/maps/place/ESKEMAN+JAPAN/@34.8793858,137.255533,3a,75y,90t/data=!3m8!1e2!3m6!1sAF1QipNkjMflYgw21O7JPtvvcyX3evtzLDa9j4oO1_An!2e10!3e12!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipNkjMflYgw21O7JPtvvcyX3evtzLDa9j4oO1_An%3Dw224-h298-k-no!7i768!8i1024!4m9!3m8!1s0x6004b9ace89a4bdd:0xfdb8efb1ba4b59bf!8m2!3d34.8793858!4d137.255533!10e5!14m1!1BCgIgAQ!16s%2Fg%2F11vk384ffj?entry=ttu 平成16年度道路施設現況調査(Tunnel.web) http://www.tunnelweb.jp/list/list.html