Right now, the Hudson Yards megaproject isn’t exactly a destination—only one office tower on the 26-acre site, which sits above and around the the Hudson Rail Yards on Manhattan’s far west side, has thus far opened to the public.

But next year will be a big one: Some of the biggest retail and cultural attractions will debut, including the highest outdoor observation deck in the western hemisphere, a seven-story mall with upscale retailers, 25 different restaurants, a fancy arts center called The Shed, and a five-acre public park centered by Thomas Heatherwick’s $150 million sculpture dubbed “Vessel.”

Not only will visitors come to the area to enjoy these attractions—up to 65,000 per day by one estimate—but apartments will have residents, businesses will have employees, office towers will have support staff, and there will still be the construction workers on the unfinished towers. Simply put, there will finally be a reason to go to Hudson Yards.

But with every new megadevelopment comes transit questions—and in the case of Hudson Yards, the question is even more pronounced, considering the land was largely undeveloped beforehand and is only served by one crosstown subway line. Can the city’s increasingly beleaguered transit system can handle the load of those 65,000 new visitors?

A key part of the development was the 7 train extension to Hudson Yards, which opened in 2015. There is plenty of room for more people in the station itself, as ridership has thus far been below projections. Back when it opened, the MTA expected 32,000 riders would use it daily, but as of 2017, the average weekday number of swipes into the station was only about 10,000. (The MTA does not release figures on station exits.)

But the larger issue is whether the 7 itself can accommodate more riders. The MTA does not release line-by-line ridership figures, but Hayley Richardson of TransitCenter says that its current capacity could be a problem. “The 7 train is hardly equipped to handle its current ridership load, much less the increase in ridership the completion of Hudson Yards will inevitably bring,” she says.

Some relief is on the way in the form of an upgraded signaling system. The 7 will be the second line in the New York subway to get communications-based train control, or CBTC, which allows trains to run closer together and at higher frequencies, therefore moving more people. The L is the only other line in the system with this technology, which allowed it to cope with North Brooklyn’s population boom by reducing platform wait times and increasing reliability.

In fact, the 7 was supposed to be operating with CBTC more than a year ago, but the project has been consistently pushed back. The hope is that it will be completed by the end of the year, and CBTC can do for the 7 what it did for the L.

The 7 train is hardly equipped to handle its current ridership, much less the increase the completion of Hudson Yards will inevitably bring.

At least in the short term, this could be enough to serve Hudson Yards, according to Christopher Jones of the Regional Plan Association, who was a bit more optimistic than Richardson. He believes CBTC should serve the development adequately for the next “several years at least.”

But that probably won’t be enough once Hudson Yards is in full bloom and more supertalls—and, crucially, more apartments, which are due to arrive in the second phase of development—are completed. A CBTC-equipped 7 line will only be able to run two additional trains per hour at peak periods, for an additional capacity of roughly 2,500 people. This is not to downplay the importance of increasing capacity by two trains, or of the reliability improvements that come with a modern signaling system. (The L line consistently operates with an on-time performance higher than 90 percent, roughly 30 percentage points better than the system as a whole.)

And Hudson Yards is a small city being constructed on the edge of a very big one, not to mention that there is plenty more development along the 7, including in Long Island City, which is in the midst of a development boom that’s rivaled only by Hudson Yards and its surrounding environs.

It’s for that reason Jones cautions, “I don’t think CBTC alone will be enough to do it.” He expressed particular concern about platform width at typically crowded stations like Times Square and Grand Central, because many straphangers will have to transfer from other lines to get to the 7, given the fact that it runs crosstown in Manhattan. Perhaps those platforms could be widened, he suggested.

This is also why Richardson believes the type of bus improvements included in New York City Transit’s Fast Forward Plan are “paramount” to making Hudson Yards viable. Those include redesigning the bus network, giving buses greater priority over traffic, enforcing existing bus lanes, and improving dispatching so buses no longer annoyingly bunch.

Richardson notes that the bus routes servicing Hudson Yards are some of the slowest in the city, and she advocates for turning 34th Street, currently the route of the M34 Select Bus Service, into a proper “busway” like the one planned for 14th Street during the L train shutdown.

But Jones cautions that buses are probably only a small part of the overall transit picture for Hudson Yards, because no matter how much priority buses have, crosstown traffic is much more difficult to move.

The reality, though, is Hudson Yards will cater overwhelmingly to upscale customers and tourists—exactly the people who have been abandoning the subway and buses in increasingly large numbers in recent years. As a recent New York City Transit analysis found, people aren’t taking fewer trips; they’re opting for-hire vehicles, such as Ubers and taxis over the subways and buses. It stands to reason those who can afford Hudson Yards’s luxury apartments, high-end restaurants, or glitzy retail may have the disposable income to avoid mass transit if they desire.

While Richardson concedes this may be the case, she cautions against assuming cars will take care of everything. “Failing to improve transit based on that prediction is defeatist public policy,” she warns, “and leaves out the entire office ecosystem of security guards, executive assistants, janitors, etc., who can’t necessarily afford to take taxis and Ubers to work.”

It’s also worth noting the roads around Hudson Yards are already jam-packed, as is much of Manhattan. If the 7 train is already crowded, the streets around Penn Station and the Lincoln Tunnel are positively gridlocked and have even less to give.

Unfortunately, the people who may be impacted the most by Hudson Yards are the ones who may not even go there. The 7 line is most crowded in the stops on the east side, western Queens, and the Jackson Heights transfer to the E, F, M, and R lines. Since Hudson Yards is the western terminal, people leaving will be boarding empty trains.

What will 7 train riders who currently board at Grand Central or transfer at Court Square face? “That in many ways,” warns Jones, “is the biggest issue.”