MUMBAI, Feb. 25 -- The state government on Tuesday issued an order approving the construction of Metro Line 8, a 34.9-km high-speed corridor to connect Chhatrapati Shivaji Maharaj International Airport (CSMIA) and Navi Mumbai International Airport (NMIA) at an estimated cost of Rs.22,862.07 crore. The project will be developed under the Design, Build, Finance, Operate and Transfer (DBFOT) framework with a 40% Viability Gap Funding (VGF). VGF is a government mechanism to provide financial grants to support economically essential but commercially unviable Public-Private Partnership (PPP) infrastructure projects. The urban development department has issued a government resolution (GR) stating that the City and Industrial Development Corporation (CIDCO) will execute the project under the PPP model. The central government and Maharashtra government will each contribute 20% of the VGF or Rs. 3,446 crore per head. The private concessionaire will bear 56.72% of the total cost, which will amount to Rs.9,773 crore, while NMIA will contribute Rs.564 crore. The order states that the state will not provide a sovereign guarantee for loans raised by the concessionaire or CIDCO. Metro Line 8 will comprise 20 stations, including 14 elevated and six underground ones. Of the total 34.9-km alignment, 25.09 km will be elevated while 9.8 km will run underground. The corridor is expected to significantly decongest key routes between Mumbai and Navi Mumbai, including the Sion-Panvel highway and Atal Setu, the Sewri-to-Nhava Sheva sea link. Since the first phase of the Navi Mumbai airport began operations on December 25, 2025, the state government has undertaken the metro link as a 'Vital Urban Transport Project' to ensure seamless airport-to-airport connectivity. This metro line is expected to reduce travel time between the two international airports. Construction of the metro link is scheduled to begin in June 2026, with completion targeted for May 2031. A 27.2-hectare metro car depot will be developed at Mandale on forest land for operations and maintenance. Operational projections indicate that trains will run at a frequency of every 5.32 minutes during the initial phase in 2031. This frequency is expected to improve to every 3.02 minutes by 2061....