HAMILTON HEIGHTS — Harlem may be getting its own version of the High Line.

The proposed project — dubbed the Harlem Promenade — would create an elevated park over a portion of the Amtrak rail lines that run along the West Side Highway.

The man-made green space would connect Hamilton Heights to existing waterfront parks on the other side of the highway by providing a safe and convenient access point.

Daniel Cohen, a West Harlem resident who works at the Housing Partnership, a nonprofit that promotes affordable housing, hatched the idea on his way home while he was looking at the rail line that separates the community from the Hudson River.

In order to pay for the park, Cohen thought of transferring the rail line's unused air rights to several buildings on Broadway. Selling those air rights would make about $170 million, which could be used to fund public projects like the Harlem Promenade, making subways more accessible, building an Amtrak station in Harlem or other community projects.

“This is an idea,” said Cohen, who has been pitching it to community members. “It’s not in any way written in stone.”

The proposal would move the air rights to Broadway and set up a special district that would bring in 2,000 units of affordable housing to West Harlem, Cohen said.

It's been done before — in Chelsea’s High Line district and Midtown’s theater district. The difference is that developers used those zones to build luxury condos and hotels, not affordable housing, Cohen said.

This special district zone would require developers to stick to a 50-50 split of market rate and affordable housing units. With the air rights, the current height limit of 12 stories would increase to 16, allowing 4,000 units to be built in the area.

Cohen has identified a dozen sites along Broadway to receive the air rights. They are all privately owned, non-residential, underdeveloped buildings that are less than three stories tall, he said.

While no residents would be displaced, businesses in the sites would have to shut down. They include banks, grocery stores, retail outlets and a health clinic. Under the proposal, developers would be given incentives to bring the businesses back, Cohen said.

The idea of bringing 2,000 units of affordable housing to a neighborhood that desperately lacks affordable housing should be taken seriously, said City Councilman Mark Levine.

But a lot of questions need to be answered, he added.

“It’s an unusual proposal because it’s not a developer,” Levine said about Housing Partnership. “This is really just creating a zoning opportunity for developers to come in. There are more unknowns here than normal.”

One of the main concerns is affordability — specifically who qualifies. The median income for families in Hamilton Heights is about $40,000 compared to $80,000 in other parts of Manhattan, said Jeanie Dubnau of the Riverside Edgecombe Neighborhood Association.

“What is affordable and for whom?” she asked. “What’s affordable for Manhattan is not affordable for our neighborhood.”

Another concern is that the special purpose district could undermine all of the previous rezoning work community advocates did a few years ago after Columbia University announced its expansion, said Yuien Chin of the Hamilton Heights - West Harlem Community Preservation Organization.

“The community invested so much time in the rezoning process hoping it would protect the historic character of the neighborhood while allowing for some controlled growth in specific areas, so this news is disconcerting,” she said.

So that local residents can benefit from the proposal, they would use area median income to determine affordability, Cohen said.

Preserving the character of the neighborhood is also part of the motivation, he said.

West Harlem is one of the last sections of Manhattan that has not seen large-scale gentrification. But developers will continue to head north, he said.

As it stands now, there is nothing preventing someone from buying one of the lots and building a 12-story luxury condo. This proposal would let the community dictate what gets built, Cohen said.

“Let’s have a role,” he said. “Lets have a say and try to create more affordable housing.”