HARRISBURG - An angry and apologetic Gov. Rendell yesterday called his administration's handling of a massive backup on a snow- and ice-covered section of I-78 "totally unacceptable" and ordered a full investigation.

"I am to blame for this, and I accept full responsibility for our inadequate and unprepared response," Rendell said at a news conference about the 50-mile tie-up west of Allentown that began Wednesday and stretched into early yesterday morning.

"I personally apologize to each and every motorist who was stranded," Rendell said.

Last night, officials of the state Department of Transportation said they planned to have I-78 and two other closed highways, I-80 and I-81, in the same region open by this afternoon.

Thick ice and frigid conditions, rather than mountains of snow, have confounded road crews.

Road salt has been largely ineffective because it does not work below 20 degrees. With temperatures in the teens all week, PennDot has brought in slow-moving, heavy machines called graders to scrape away ice, officials said.

Rendell said James Lee Witt, a former director of the Federal Emergency Management Agency who now runs a public-safety consulting firm, would conduct an independent investigation into the snow snarl that made national headlines when hundreds of motorists were trapped in their vehicles for as long as a day.

Asked whether anyone would be fired, Rendell said: "We'll see."

The situation was set in motion late Wednesday morning by a tractor-trailer accident that closed the eastbound lanes of one of the nation's most heavily-traveled truck routes amid a snow and ice storm.

Access ramps remained open for hours after the accident, allowing hundreds of vehicles to pour onto the road, only to become trapped between exits.

By the time PennDot and state police closed the highway and the access ramps, the backup stretched for 50 miles.

Rendell said the investigation would focus on why only some ramps to I-78 were blocked; why no salting was done early Wednesday, when traffic was light; and, particularly, how a communications breakdown let eight hours go by before he was notified of the situation.

With wreckers unable to clear the disabled trucks because of the jam of vehicles, plows were unable to move snow, and thousands of vehicles were trapped on a mountainous stretch of road overnight, their occupants facing wind-chill temperatures in the single digits.

One section of I-80 between Routes 209 and 33 and I-380 in Monroe County was reopened yesterday afternoon, but maintenance crews were expected to work through the night to clear thick coats of ice, in some places six inches deep.

Rendell lambasted his own interagency communications, saying he was not notified of the event until 8 p.m. Wednesday - at least eight hours after the backup began.

Rendell appeared incredulous that it was a member of his private security detail, not emergency agency officials, who notified him at his home in Philadelphia. "It was a total breakdown in communications," he said.

Rendell aide Kate Philips said, "Clearly, we don't need an investigation to show there was total breakdown in communications. If that didn't happen, we would likely avoid much of what happened."

Rendell said he activated the National Guard immediately, and that 500 troops were dispatched to rescue motorists who needed medical help and to deliver food, water and fuel to those who stayed with their vehicles.

Lawmakers from both parties, including one who was trapped on her way home from Harrisburg, and others from the three-county region where the backup happened had strong words about the state's storm response.

"The delay was unforgivable," said State Rep. Jennifer Mann (D., Lehigh), who was stuck for almost six hours before reaching an exit ramp via an unplowed shoulder. "I expected a major interstate would be passable and it was not."

Mann said she saw no emergency personnel or road workers, and added the state was lucky there were no fatalities.

"We dodged a major catastrophe," she said.

The Senate Transportation Committee and Senate Veterans Affairs and Emergency Preparedness Committee scheduled a hearing for Feb. 22 to assess the state's response.

Some Republican House lawmakers yesterday called on Transportation Secretary Allen Biehler and State Police Commissioner Jeffrey B. Miller to explain what happened.

"Why weren't people telling [Rendell] what happened? The question members have is: Who was minding the store?" said State Rep. Doug Reichley (R., Berks), who was one of four GOP lawmakers who sent a letter to the agency heads yesterday.

Until the roads are cleared, motorists will be forced to detour around stretches of I-78 between Fredericksburg and Fogelsville. Drivers will be banned from I-80 between Lime Ridge and the I-380 junction; and from I-81 between Fort Indiantown Gap and Wilkes-Barre.

To help drivers, the toll waiver on the Pennsylvania Turnpike has been extended through tomorrow, officials said.

A Winter Emergency Kit for the Car

The best defense against being stranded on impassable roads is not to drive in severe weather. Throughout the winter, however, motorists are advised to carry key emergency items:

Fully charged cell phone.

Shovel.

Jumper cables.

Blanket.

Ice scraper.

Windshield wiper fluid or de-icer.

Paper towels.

First-aid kit.

Flashlight.

Small fire extinguisher.

Cat litter for traction.

Water and/or granola bar.

Lock de-icer.

Source: AAA Mid-AtlanticEndText

Contact staff writer Amy Worden at 717-783-2584 or aworden@phillynews.com.

Inquirer staff writer Michael Currie Schaffer contributed to this article.