HARTFORD, Conn. - Traffic in southwest Connecticut could be a mess for as much as a week until service is restored to the commuter rail line affected by a derailment that injured scores of passengers, Gov. Dannel P. Malloy warned Sunday.

Malloy used dire language to describe traffic troubles for the workweek ahead in an area that even in normal times is a pain for motorists. And the governor warned that the weather would not cooperate, as the forecast of rain would make driving a bit more treacherous.

Malloy even urged commuters to stay out of the state if possible.

"Tomorrow's commute will be extremely challenging," he said at a brief news conference in Hartford. "Residents should plan for a week's worth of disruptions."

If all 30,000 affected commuters took to the highways to get to work, "we would literally have a parking lot," the governor said. If a substantial number of affected consumers hit the roads, he said, traffic would be "greatly slowed."

The state will dispatch additional state troopers and tow trucks to respond to car accidents that could come with crowded roads and slippery conditions, he said.

"If you are going to New York . . . you may decide that perhaps you should stay there for the duration of this disturbance," Malloy said.

Crews will spend days rebuilding 2,000 feet of track, overhead wires, and signals following the crash between two trains Friday evening that injured 72 people. Nine remained hospitalized, one critically.

"This amounts to the wholesale reconstruction of a two-track electrified railroad," Metro-North President Howard Permut said Sunday.

Several days of round-the-clock work will be required, including inspections and testing of the newly rebuilt system, Permut said. The damaged rail cars were removed from the tracks Sunday, the first step toward making the repairs.

Starting with the Monday-morning rush-hour, a shuttle train will operate about every 20 minutes between New Haven and Bridgeport, and two shuttle buses will run between Bridgeport and Stamford stations, state transportation officials said.