A new central terminal for LaGuardia Airport will be completed by 2022 and feature two pedestrian bridges travelers can use to walk above airplane taxi lanes while moving between the terminal and the two concourses where aircraft park, the project’s developer said Wednesday.

Developer LaGuardia Gateway Partners said the use of bridges and island-like concourses was a first for an airport.

And the separate concourses would allow greater flexibility in moving planes in and out quickly, although the number of slots for planes will remain unchanged at 35, the developer said.

The existing Terminal B is used by eight airlines, including American, Jet Blue and United. Negotiations are continuing for the redevelopment of Terminal C to the east, home to Delta Air Lines.

The new Terminal B and related work will cost about $4 billion and be funded through public and private funds. The terminal will be built and operated by the private partnership under a lease, signed Wednesday, that runs through 2050.

In addition, the terminal will have food, retail and beverage outlets beyond the security screening area and more seats for waiting passengers than the current terminal.

Plans for the airport modernization come as the travel industry and the public struggle with long security lines and wait times, particularly at New York City’s three busy major airports — LaGuardia, Kennedy and Newark Liberty.

The new central terminal at LaGuardia will take into account “the realities of post-9/11 air travel, with additional space for security check-in to help diminish wait times for passengers as they pass through mandatory TSA screening,” Gov. Andrew M. Cuomo said in a statement Wednesday.

Unlike the current Terminal B, where travelers must pass through a separate security checkpoint to access each of the four main concourses, once completed, the new Central Terminal Building will feature one security checkpoint providing travelers with access to all concourses, according to LaGuardia Gateway Partners.

“It’s going to be the airport that New York State deserves,” Cuomo said earlier at a Manhattan news conference with members of the partnership.

He said the current facility was “not really a single airport. It is a series of terminals. It’s going to be a unified airport.” However, he noted that negotiations with Delta on its new terminal had not been finalized.

Cuomo also said planning was continuing on a possible public rail link to LaGuardia. He did not elaborate.

LaGuardia, which Vice President Joe Biden likened to a ‘‘Third World airport,’’ Kennedy and Newark Liberty have experienced “abysmal” security wait times in 2016, according to the Port Authority, which runs all three facilities.

Terminal B at LaGuardia was built in 1964 to accommodate 8 million travelers annually, and now handles more than 14 million, said Pat Foye, executive director of the Port Authority.

A spokesman for LaGuardia Gateway Partners, which took over operations Wednesday from the Port Authority, said it has a strong relationship with the Transportation Security Administration, which operates screening lines, and would work with it to improve passengers’ experience in the existing terminal.

The lease signing for the project came on the same day as the first concrete step in the lengthy redevelopment: the closing of parking lot P3, with 920 spaces just to the east of Terminal B.

The 2,700-space parking garage B will close in July, and a new lot, P10 will open July 8 near the old Marine Air Terminal. Travelers can take a shuttle bus from there to the terminals.

“Construction requires the closure of several parking lots, limiting available parking,” a Port Authority advisory said. “Instead of driving, customers are urged to find other means of transportation to the airport.”

The current terminal will remain open during construction of the new one, and flights will not be affected, the partnership said.

“We are committed to delivering this project on time and within budget, while keeping communities engaged and informed,” Stewart Steeves, CEO of the partnership, said.

LaGuardia Gateway Partners includes Vantage Airport Group, an airport manager and operator; Skansa USA, a construction firm; Walsh, an aviation contractor, and Meridiam Infrastructure, an investment and development firm.