UPDATED: 1:00 p.m.
According to the American Transportation Research Institute, they are:
No. 38. The Schuylkill Expressway and I-676 interchange in Philadelphia
No. 63. The Blue Route and I-95 interchange in Delaware County
No. 77. The Schuylkill Expressway at the Blue Route near Conshohocken
No. 90. The I-76 and I-676 interchange in Camden
According to the study, the trucking industry loses a little more than a billion plus hours of productivity and $74.5 billion each year because of congestion on the highways throughout the country.
Dick Voith, president of Econsult Solutions, is an expert on the economics of transportation. He says he's not surprised the Philadelphia area is well represented.
"When you look at our road system, it's old. There are some new components, (476 is only 28 years old) but it's tough to add capacity," he said.
Voith says traffic jams lead to many hours of lost productivity, and the economic might of the Philadelphia-area takes a big hit.
"You have all these people waiting, and their time really is money. And we're competing with other regions," Voith said. "And that is an economic consideration when people locate."
Voith says there has been improvement. Many more people are working closer to home or rely on public transportation than in the past. And looking to the future, he says, what could make a big impact is automation, especially in the trucking industry.
"It's gonna be complicated, but I think it will ultimately allow more commerce through the same spatial geography."
See the complete list at the American Transportation Research Institute website.