The PATH train, already bursting at the seams, stands to get more crowded amid a building boom in northern New Jersey, in another sign the transit network is straining under the region’s population growth.

Apartment buildings springing up in Jersey City and communities nearby are funneling new riders onto the PATH, whose lines run to the World Trade Center and Herald Square in Manhattan.

Many passengers complain of crammed commutes, or having to wait for trains to pass before boarding one that isn’t packed—an experience familiar to many New York City subway riders.

“It’s just miserable,” said Elliot Kelly, 24 years old, who rides the PATH from Jersey City each weekday morning to work at a law firm in Manhattan. “It’s never nice to make a commute when you’re 3 centimeters from someone else’s body.”

As the PATH’s operator, the Port Authority of New York and New Jersey, considers improvements to expand the system’s capacity, questions linger over when they will be completed and who should pay for them.