Subway riders that trudge through the crowded platforms of Grand Central station are set to get some respite, though relief is still more than five years away.

More than $200 million in improvements to the terminal area that will help the flow of passengers arriving at Grand Central will be handled by the developers building One Vanderbilt -- a 65-story skyscraper from SL Green that will be nearly 1,400-feet tall and sit across the street from the iconic terminal.

The developer, which detailed the proposed changes to the station for reporters Monday, is footing the bill, overseeing the construction and handling any cost overruns, according to SL Green managing director Robert Schiffer.

"It is our project to build, not the MTA's," he said.

Riders on the cramped Lexington Avenue lines will have more room to walk with slimmer staircases and columns on the express side of the platform. That extra space means passengers can get on and off faster so that the subway is not stuck in the station waiting, allowing the MTA to run an additional train each hour.

There will also be a two new street-level subway entrances on the overcrowded Lexington Avenue No. 4, 5 and 6 lines, a staircase in the basement of the Pershing Building to connect the subway mezzanine to the platform below and an escalator to the street next to the 42nd Street shuttle. Closed-off space in the subway station's mezzanine will also be opened up for better circulation of riders.

The centerpiece for One Vanderbilt will be a 4,000 square-foot ground-level indoor waiting area for passengers to wait for Metro-North trains and Long Island Rail Road, which will be able to get into Grand Central Terminal when the MTA's East Side Access project is complete in 2023. Above-ground, cars will be blocked from Vanderbilt Avenue between 42nd and 43rd streets for a pedestrian plaza.

The developer is planning to start the public review and approval process for the projects this month and finish March 2015. The design and construction are expected to finish by January 2020.

"We have fallen behind and regional transit users are getting crushed in Grand Central and it is not sustainable," said Councilman Dan Garodnick, who co-chairs a panel with Manhattan Borough President Gale Brewer that will make recommendations on how to develop East Midtown.

The de Blasio administration in May allowed SL Green to submit a plan to build One Vanderbilt so that transit improvements will be made before the new building opens for business and East Midtown undergoes a rezoning to allow denser, modern skyscrapers.

"Before the first office worker walks through the doors of this new building, we will have in place improvements to subway platforms, concourses and entrances that will increase capacity at Grand Central and make life easier for thousands of commuters," Deputy Mayor Alicia Glen said in a statement.