They were scheduled to be replaced by this year with double-decker cars that carry more passengers and have pairs of individual seats instead of benches that hold three people. But those new cars are not due for at least three years, leaving riders frustrated and pleading for relief.

“Why can’t we have those nice double-deckers?” said Nicole Zamarripa, who said she usually winds up on one of the cramped, old trains each way on her commute between New Brunswick, N.J., and Manhattan. “Either the brown leather ones or the ugly green, plasticky ones,” she said, alluding to the interiors of the old coaches.

Ms. Zamarripa, 25, said she does not use anything else in her life as old as those train cars.

When the coaches were built in the 1970s, nearly 20 years before her birth, their early riders did not have cellphones or laptop computers. They had yet to drink a Diet Coke or a Bud Light or lace up a pair of Nikes, but many of them smoked cigarettes aboard the trains, a practice that was not banned until the mid-1980s.

On a recent weekday, Ms. Zamarripa tweeted her frustration at watching a “basically empty” double-decker leave New York City as she sat on a packed, single-level train in the tunnel under the Hudson River.