Everything You Need to Know About NYC's New Interborough Express Train

A new mass transit line would connect Brooklyn and Queens.

Train station rendering for IBX

The outer boroughs can often feel like an afterthought when it comes to the New York City subway system. The oft-forgotten G Train is currently the only subway line running directly between Brooklyn and Queens, but Governor Kathy Hochul is hoping to change that with a plan for a new mass transit line dubbed the Interborough Express (IBX).

Although there are many funding and construction hurdles to clear before the IBX could get the chance to whisk its first passengers across the city, the initiative appears to have fairly broad support from local politicians and community groups. So here's what you need to know about what could become NYC's newest transportation line.

Who Will It Serve?

The IBX would run on a pair of pre-existing right-of-ways called the Bay Ridge Branch and the Fremont Secondary, which stretch from South Brooklyn to central Queens. They haven't carried passenger rails since 1924, although freight trains still run there. The plan outlines stops in neighborhoods like Bay Ridge, Borough Park, Flatbush, Canarsie, Brownsville, and Bushwick in Brooklyn, as well as Ridgewood, Maspeth, Middle Village, and Jackson Heights in Queens. It would connect to as many as 17 subway lines (2,3,5,7,A,B,C,D,E,F,J,L,M,N,Q,R,Z), and would run from end to end in less than 45 minutes.

The neighborhoods the IBX would serve are over 70% non-white. Half of all residents in these areas don't own a car, and one in four have limited fluency in English. Several of the neighborhoods are considered transit deserts, and the MTA estimates the line would attract around 85,000 riders per day.

Versions of the plan have existed since the late '90s and have at times attempted to continue service through Astoria into the South Bronx. However, according to the MTA, recent feasibility studies found that the Hell's Gate bridge between Queens and the Bronx—already used by Amtrak and MetroNorth—can not handle the additional capacity that the IBX would generate.

Map of the proposed Interborough Express
Image courtesy of the MTA

What Kind of System Will It Be?

The MTA's current plan outlines three possible systems: a conventional commuter rail akin to the Long Island Railroad or MetroNorth, a light rail system more like a subway train, or a bus rapid transit system. Each has its drawbacks, and the MTA has yet to commit to a specific mode.

Due to federal regulations, only traditional rail is allowed to share tracks with freight trains, necessitating parallel or "flyover" tracks for any light rail system. Bus lanes running parallel to existing railroad tracks would have their own engineering challenges, while traditional rail would be the slowest of the three options.

Courtesy of Governor Kathy Hochul

How Much Will It Cost?

The real question on everyone's mind is the cost. The MTA is famous for its ballooning budgets, with projections for Phase II of the Second Avenue Subway recently coming in at $3.5 billion per mile. While the IBX will have to contend with the same high labor costs, it benefits from the existing infrastructure.

The line is almost entirely separated from the surrounding community with embankments or trenches, and there are already rail tracks in place. The MTA has not released a specific cost estimate yet. Still, experts told StreetsBlog New York that—depending on station designs and engineering challenges related to bottlenecks—the price tag could be much lower, in the "single-digit billions" range for the entire 14-mile build-out.

When Will It Open?

New York isn't exactly known for its speedy transit construction timelines, as anyone waiting for the Second Avenue Subway can tell you. In early January, Governor Hochul revealed her IBX plan during her State of the State Address and announced last week that it had passed a feasibility study. The project must now go through community outreach, environmental review, engineering, and design processes, and secure funding before construction could begin. NYC could be looking at a potential IBX opening closer to the end of the decade.

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Chris Mench is an editor focusing on NYC News at Thrillist. You can follow him on Twitter for more of his work.