Any train that was not rerouted had to be manually directed through the station, a particularly time-consuming process, according to the Metropolitan Transportation Authority, which operates the subways. Because the system’s lines are so intertwined, a ripple effect was almost inevitable. A spokeswoman for the authority likened it to cars being diverted from a highway to local streets. Gridlock ensued as other subway stations dealt with the resulting overflow.
“The subway system’s strength is also its weakness,” said Gene Russianoff, staff attorney for the Straphangers Campaign, a rider advocacy group.
Long Delays and Frayed Nerves
Delays stretched across the city on the B, D, F, M, A, C, E, F, J, Q, G and R trains — more than half of the system’s 22 main lines. Some A trains were stuck in Brooklyn for more than 40 minutes. G trains stopped underground between Brooklyn and Queens. Commuters stewed.
One train operator told a packed car of frustrated riders to take note of their subway car’s number. “Write it down and tell your boss.” Many of those bosses got stuck themselves. A lack of information about what was happening and what options might be available exacerbated the dissatisfaction of many commuters.
Harsha Penna, 34, an engineer who lives Jersey City and commutes to work in Queens, spoke to a reporter at the station where the problems started after the operator of his train had told everyone to get off. Much of the station was dark, the turnstiles were not working, and an escalator had stopped moving. A set of fluorescent bulbs flickered on and off.
“I’ve taken three trains this morning,” he said, “and I’m nowhere now.”
A System Showing Its Age
Subway experts said that aging infrastructure had made the system’s problems worse. Some stations date back more than 100 years. Some subway cars in use today were introduced when Lyndon B. Johnson was president. And some of the signal operations, particularly along the lettered lines, predate World War II, said Richard Barone, vice president for transportation at the Regional Plan Association.
“When you’re running century-old infrastructure, problems have a tendency to cascade through the entire city,” said John Raskin, the executive director of the Riders Alliance, a transit advocacy group. “And that’s part of what we experienced. With modern infrastructure, it is easier to isolate problems, build in redundancy and limit the impact when something goes wrong.”
Seeking More High-Tech Help
Infrastructure improvements might not keep things from going wrong, but new technology could help reduce delays when they do, transit advocates said.
About 10 years ago, the authority finished installing a computerized network, Automatic Train Supervision, to improve signal information on the numbered lines from 1 to 6. The system has been credited with helping reduce delays. There are plans to add it on the lettered lines, the authority said, but it had not been fully installed on most of those that experienced delays on Friday. It is not the most modern system — the project began in the 1990s — but advocates said adding it on other lines could help.
Mr. Barone of the Regional Plan Association, which studied the signal systems in 2014, said that Automatic Train Supervision allowed operators to make more informed decisions by giving them more information about trains in tunnels.
“The faster they can get the big picture together, the faster they can start addressing problems so things don’t cascade so quickly,” he said. “I don’t think it would eliminate the impact — there would still be problems — but hopefully they wouldn’t be as severe.”
Beth DeFalco, an authority spokesman, said that “A.T.S. would have had no impact or offered no benefit to today’s incident.”
One especially useful technology, a more responsive computerized system known as Communications Based Train Control, has been installed on the L line and is being developed for the No. 7 line.