Indian Prime Minister Narendra Modi is set to inaugurate two landmark transit projects worth nearly $4 billion on Wednesday, marking another milestone in his administration’s effort to modernize infrastructure in the world’s most populous country.

Modi will preside over the launch of the Navi Mumbai International Airport on Wednesday alongside billionaire Gautam Adani, whose conglomerate the Adani Group developed the project. Modi will also ring in the completion of the final phase of the newest metro line connecting southern and central Mumbai via the city’s first underground track.

The projects come online as the seaside metropolis pushes to overhaul its infrastructure and billions of dollars gush into logistics projects across the country.

Federal and state government spending is on the rise and assets in so-called infrastructure investment trusts, which allow individuals to invest in projects, are expected to surge in the coming years.

Still, India faces a large funding gap and a rapidly growing urban population that risks overwhelming already strained public systems. Consequently, the administration is taking steps, such as rolling out a government program last month aimed at attracting long-term investors like pensions and life-insurance companies.

The airport — built to resemble a lotus, India’s national flower — will span over 1,160 hectares in Navi Mumbai, a satellite city east of Mumbai. It’s designed to handle 90 million passengers per year over time and will be India’s first airport to be connected by a water taxi.

The new terminal is expected to ease aviation bottlenecks at the city’s sole existing airport that’s already hemmed in with slum clusters on one side. It would also boost development of real estate in the surrounding area in Navi Mumbai.

The new airport "will ease the capacity constraints in the Mumbai region” and strengthen connectivity, said Sheldon Hee, regional vice president Asia-Pacific at the International Air Transport Association. The IATA will collaborate with the Navi Mumbai airport team "to deliver the required capacity efficiently, foster innovation and create a seamless experience for passengers and stakeholders,” he said.

Commercial flight operations are expected to begin in December, Adani Airport Holdings’s Chief Executive Arun Bansal said at a news briefing on Monday. Initially, it will have the capacity to handle 20 million passengers every year, he said, adding that the group will invest another 300 billion Indian rupees in the second phase of the airport's development.

The Adani Group is developing the greenfield airport through a special purpose vehicle, Navi Mumbai International Airport Pvt, in which the conglomerate’s airport unit holds a majority stake of 74%. The state-owned City and Industrial Development Corporation of Maharashtra holds the remaining 26%.

Modi will also inaugurate the final phase of Metro-3, known as the Aqua Line, the city’s first underground metro line. The line will connect the city’s southern peninsula to the northern suburbs and offer access to the existing airport, alleviating severe overcrowding on the rail system and congested streets.

It will also connect to the Bandra Kurla Complex, the city’s major business district, where construction has started on the terminus for India’s first high-speed rail service. The bullet train will connect Mumbai to Ahmedabad, the largest city in Modi’s home state of Gujarat.

The metro system is being financed by groups including the Asian Development Bank, the Japan International Cooperative Agency, and the Asian Infrastructure Investment Bank.