Shikoku Regional Development Bureau to open Amino Tunnel construction bidding

The Shikoku Regional Development Bureau of the Ministry of Land, Infrastructure, Transport and Tourism announced in the Official Gazette (Extra Edition for Government Procurement) dated September 18, 2026, that the FY2026/2029 Kaifu-None Road Nukumi Tunnel Construction Project will be subject to general competitive bidding. The Expenditure Burdening Officer is Akihisa Okuda, Director-General of the Shikoku Regional Development Bureau. The project has been announced as subject to electronic bidding and electronic contracting.

The construction site extends from Nukumi to None in Toyo Town, Aki District, Kochi Prefecture. The total construction length is 1,100 meters, of which the tunnel length is 822 meters. The project involves one set of tunnel work using the NATM method for blasting excavation, with a width of 12 meters and an internal cross-sectional area of A=98. The procurement agency number is 020 (Ministry of Land, Infrastructure, Transport and Tourism), location number 37, and item classification number 41.

Construction Period with Optional Start Date and Buffer Period

• Construction Period: 1,065 days from the start of construction (if the end date falls on a weekend, public holiday, or New Year holiday, it shall be the next business day following the holiday).
• Buffer Period indicated by the orderer: From the day following the contract conclusion date until March 31, 2027.
• If a contract is not concluded within the buffer period due to low-bid price investigations, etc., the buffer period will not apply, and the construction completion deadline will be February 28, 2030.
• During the buffer period, the assignment of the planned engineer is not required, and preparations for materials not yet delivered to the site are permitted.

Technical Proposal Evaluation Type Assessing Non-Price Factors

This project is subject to the Comprehensive Evaluation Bidding System (Technical Proposal Evaluation Type), where technical proposals are accepted, and the successful bidder is determined by comprehensively evaluating non-price factors and price. It is positioned as a pilot project for the “Technical Proposal Evaluation Type (S-I Type),” which requires “technical improvement proposals” that allow for minor changes to the design documents, in addition to the standard technical proposals required by the Technical Proposal Evaluation Type S-Type.

Qualification Notice for Specific Construction Joint Ventures Issued on the Same Date

On the same day, the Shikoku Regional Development Bureau published the application method and other details for those seeking qualification to participate in the competition as a Specific Construction Joint Venture for this project.

• Name of the Joint Venture: Shall be “FY2026/2029 Kaifu-None Road Nukumi Tunnel Construction [Name] · [Name] Specific Construction Joint Venture.”
• At the time of the bid opening, the entity must have received qualification certification as a Specific Construction Joint Venture and must have had its qualification for competitive participation confirmed as indicated in the bid announcement for this project.
• The notice was issued under the name of the Expenditure Burdening Officer, Akihisa Okuda, Director-General of the Shikoku Regional Development Bureau.

This project is a large-scale public mountain tunnel project ordered by the Shikoku Regional Development Bureau and represents a procurement opportunity for construction companies in the Shikoku region. Participation as a joint venture is expected in addition to individual participation, and construction track records and technical proposal capabilities will influence the winning bid.

Source: Official Gazette (Extra Edition, Government Procurement) dated September 18, 2026, Shikoku Regional Development Bureau “Invitation to Bid (Construction Work) FY2026/2029 Ambe-None Road Nukumi Tunnel Construction” (Expenditure Authorizing Officer: Director General of Shikoku Regional Development Bureau, Akihisa Okuda), and the same “Public Notice Regarding Qualifications for Competitive Participants” (Specified Construction Joint Venture).