The eastbound crashes were reported just before 8:30 a.m., in the middle of rush hour and about five hours after a storm that dropped a foot of snow in the area finally moved out.
Speed restrictions put in place during the storm had been lifted at 6 a.m., but rush-hour motorists said the roadway was very slick, calling into question whether it had been adequately treated. State police also suspect sun glare might have played a role.
The accidents created a five-mile traffic jam between the Bensalem and Willow Grove exits of the state's primary east-west highway. The jam was cleared by the middle of the afternoon, and turnpike officials reopened the roadway in both directions by 4 p.m.
Stuck motorists turned off their engines to conserve gas. One of them, Chuck Wacker, 53, of Plymouth Meeting, counted about 30 smashed-up vehicles around him.
"It's a pretty calm atmosphere right now," he said. "People are sharing food and water."
He said cars were spun around, gas tanks were cracked open and glass and plastic littered the road.
Ambulances took 30 people from the scene, but none of the injuries were believed to be major, turnpike spokesman Bill Capone said. Abington Memorial Hospital and St. Mary Medical Center received many of the patients, but spokeswomen at the two facilities said none of the injuries was life-threatening.
State police were investigating the cause of the pileups, but a spokesman said sun glare, icy conditions and excessive speed likely contributed.
"The road looked wet, when in reality it was patches of ice," said Trooper Adam Reed, a state police spokesman.
Turnpike officials said they had lifted speed restrictions based on road conditions at the time.
"Based on reports from the road crews, the roads were such that we could restore it back to normal posted speeds," Capone said. "If somebody had said there was still a reason to keep it in place, we would've kept it in place."
Whether conditions changed after that decision would be part of the state police investigation, Capone said. He said he was told the road had been treated, but couldn't say when.
Several motorists interviewed by The Associated Press described an icy, slippery highway.
"I expected this road to be clear," said Dan Santillo, 65, of Jeffersonville, who was stuck about a mile back. "A major thoroughfare like this? It actually has pieces of ice that were never removed or salted. It just didn't make sense."
Santillo said he was driving 40 to 45 mph, but other motorists were flying by him at 65 or 70.
"I was thinking, what the hell are people doing? It's icy. They're crazy," he said. "People have this false sense of security. I was shocked. Don't they see the road, see what I'm seeing?"
David Hill, 27, said he wasn't surprised there was an accident.
"I got on the turnpike and it was nothing but ice," he said. "I was very surprised at the condition of it. Normally the turnpike is one of the first roads that's cleared, but today I was driving on solid ice."
Joe Dieckhaus was driving to work in Bristol when he saw a tractor-trailer ahead of him jackknife, apparently as the driver tried to avoid cars stopped in front of him. A packed van destined for the airport and a pickup then slammed into the tractor, while the trailer swung over the top of a Mitsubishi, Dieckhaus said. The Mitsubishi driver escaped out his window.
"It was a bit of a nightmare," said Dieckhaus, who managed to swerve onto a shoulder and avoided the crash.
"There was so much ice out here. This thing really should have been shut down and salted," he said.
Motorists trapped in the traffic jam seemed mostly to be taking their predicament in stride, despite having already been stuck for several hours. Santillo, who had picked up a dozen heart-shaped doughnuts to take to work, passed them out to fellow motorists instead.
Volunteers from The American Red Cross of Southeastern Pennsylvania headed to the scene to bring food, water and blankets to stranded motorists.