北海道新幹線の札幌延伸開業､2030年度末から｢未定｣へ 小樽―長万部間の並行在来線廃止も｢未定｣？ Estimated opening year of the extension of Hokkaido Shinkansen to Sapporo is pushed back from 2030 to "Unknown", which means that abolishment of the …