Hartford - 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 will not cooperate as rainy forecast will 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, traffic will be "greatly slowed," he said.

The state will dispatch more 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 and you get to New York or you're transporting yourself 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 collision between two trains Friday evening that injured 72 people. Nine remained hospitalized, with one critically.

"This amounts to the wholesale reconstruction of a two-track electrified railroad," he said.

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

Starting with this morning's 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.

For morning and evening peak commutes, limited train service will operate between Grand Central Terminal and Westport.

State officials said travel times will be significantly longer than normal and trains will be crowded. Commuters are advised to use the Harlem line in New York.

Amtrak service between New York and New Haven was also suspended and there was no estimate on service restoration. Limited service was available between New Haven and Boston.

Jim Cameron, chairman of the Connecticut Rail Commuter Council, said he's asked officials in numerous towns to suspend parking rules to accommodate what could be tens of thousands of motorists driving to unaffected train stations. Twelve stations are affected by the shutdown.

But Cameron said he doubts many commuters will use three modes of transportation to get to work: driving their cars to catch a bus to get to a train station for the final leg.

He suggested that local and regional officials post highway signs directing motorists to available parking so motorists "don't get off the highway and drive in circles looking for where to dump their cars."

About 700 people were on board the trains Friday evening when one heading east from New York City's Grand Central Terminal to New Haven derailed just outside Bridgeport. It was hit by a train heading west from New Haven.

Dan Solomon, a trauma surgeon who lives in Westport and was headed to work at Yale-New Haven Hospital in New Haven, was on the train that derailed. He said he treated several injured passengers, including a woman with severely broken ankles.

He said he was in a front car that was not as badly affected as cars in the rear of the train.

"I hardly lost my iced tea," Solomon said in an interview.

Solomon said walls were torn off both trains and he quickly checked injured passengers to separate the most badly injured from others.

"When the EMS arrived, I was covered in everyone's blood," he said.

Investigators are looking at a broken section of rail to see if it is connected to the derailment and collision. Officials said it wasn't clear if the rail was broken in the crash or earlier.

NTSB investigators arrived Saturday and are expected to be on site for seven to 10 days. They will look at the brakes and performance of the trains, the condition of the tracks, crew performance and train signal information, among other things.

The MTA operates the Metro-North Railroad, the second-largest commuter railroad in the nation.

The Metro-North main lines - the Hudson, Harlem, and New Haven - run northward from New York City's Grand Central Terminal into suburban New York and Connecticut.

The last significant train collision involving Metro-North occurred in 1988 when a train engineer was killed in Mount Vernon, N.Y., when one train empty of passengers rear-ended another, railroad officials said.