New York - Officials announced a plan to supply partial power to a heavily trafficked line of the nation's second largest commuter railroad as tens of thousands of commuters took to the highways and continued to scramble for alternative routes after a power failure disrupted service along the line serving New York City and the densely populated Connecticut suburbs.

New York-based utility Consolidated Edison was setting up three transformers to try and supply the needed 27,000 volts of power to a high-voltage line that failed Wednesday at a suburban New York Metro-North Railroad station, Connecticut Gov. Dannel P. Malloy said at a news conference in New York City's Grand Central Terminal Thursday evening.

But it was unclear how many electric trains could be served by the transformers' power, which would take power from lines in residential areas and step them up to reach the needed 27,000 volts, Malloy and Con Ed said. Officials said they'd be testing the alternative power source over the weekend to see whether it could work.

A second high-voltage line serving the trains to New Haven had been out of service for two weeks for planned repairs, officials said, and it was unclear whether its absence caused extra strain on the line that failed Wednesday.

The Metropolitan Transit Authority, which oversees Metro-North, and Con Ed both said Thursday they believed full service could be maintained by the single feeder line. It hasn't been determined what caused the outage.

Meanwhile parts of Interstate 95 turned into a virtual parking lot for much of Thursday as commuters facing hours-long delays took to the roads despite warnings that the problem could last for weeks.

"I'm the governor of 125,000 pretty unhappy commuters right now," said a frustrated Malloy, calling the service disruption "a horrendous situation."

Metro-North has said it could accommodate about 33 percent of its regular ridership and has urged customers to stay at home or find alternative transportation. Twenty-four diesel trains have been running Thursday, said a MTA spokesman, in addition to about 60 shuttle busses.

At Grand Central Terminal on Thursday, ticket windows for the New Haven 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. 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.