On October 1, 2005: Due to the Privatization of Four Highway Public Corporations the transfer of ownership to Japan Expressway Holding and the Debt Repayment and Agency took place, and the management was tranferred to West Nippon Expressway Company Limited
2005年10月1日：道路関係四公団の民営化により、保有を独立行政法人日本高速道路保有・債務返済機構に、管理を西日本高速道路株式会社に移管。