At Grand Central Terminal on Thursday, ticket windows for the New Haven, Conn., line were closed. Commuters who rode other lines said those trains were more crowded than usual.
Matt Sullivan, 27, an architect, said it usually takes him half an hour to get to Grand Central from his home in Greenwich, Conn. That doubled when he drove into New York's White Plains and took the Harlem line.
"It's disappointing but my company will give me a laptop so I can work from home a couple of days," he said.
The broken circuit could take two to three weeks to repair, Consolidated Edison has said.
"Some of us can't telecommute," said a frustrated Moe Ferrara, 29, of New Rochelle, whose 30-minute commute has doubled since the outage, after waiting for the few crowded diesel trains that were still running.
"What are my increased fares going toward?" she asked. "You don't see the results of these increased rates."
Amtrak said it would offer limited service between New York and Boston on Thursday because of the power problem.
Associated Press writers Karen Matthews and Verena Dobnik in New York, Susan Haigh in Mashantucket, Conn., and Stephen Singer in Hartford, Conn., contributed to this report.