SAVAGE, Md. — About 110 million people live along I-95. On a summer weekend, it can feel like all of them are on the road.
Transportation officials are warning the collapse of an overpass on I-95 in Philadelphia on Sunday is likely to jam tractor-trailers, tourists and business travelers for weeks.
"We're trying not to think about it," said Brian Ahnmark, who was cradling his toddler on a pitstop as he headed to New York from Richmond. "Hoping that if we ignore the concept of traffic, everything will be ok."
At the I-95 rest stop near Laurel, travelers headed north bracing for the worst.
Girmachew Tessema was planning to take I-295 and the Delaware Memorial Bridge as he returned home to New Jersey, but he was worried way too many people would be detouring that way too.
"Then we'll have a problem," he said laughing nervously. "We'll be there awhile."
Highway warning signs were flashing up and down the corridor Monday saying I-95 is closed in Philadelphia. The Maryland Department of Transportation said alternate routes are likely to be jammed, too.
"On the Delaware Bridge headed back, it was another five miles of traffic for sure, which is not usually the case on a Monday," said Terry Head who was driving south for Mason Neck Virginia after a weekend at the Jersey beaches.
Crews were already racing to remove the rubble, but Transportation Secretary Pete Buttigieg warns the trouble is likely to continue for a while.
"This is going to be a major disruption in that region," he said.
An estimated 160,000 vehicles cross the now broken overpass every day. Drivers rolled across it even as the flames were shooting out from underneath before it collapsed.
"I felt it drop like a rollercoaster, and I was like, 'Oh that wasn't very smart', because I could've fallen into the fire," said motorist Frank Graber.
Structural engineer Allyn Kilsheimer -- who helped repair the Pentagon after 9/11, and steady the Washington Monument after an earthquake -- suspects braided wires through the overpass's pre-cast concrete failed as 8,500 gallons of gas spilled from a tanker and burned, killing one person.
"If you have all these wires and you start breaking the wires, it can no longer carry itself, so it breaks," Kilsheimer said.
But Kilsheimer said it's impossible to prepare for every possible catastrophe.
"If they want to design for a hurricane, you say, 'How big a hurricane and from what direction,'" he said. "If you want to design it for a bomb, you say, 'How big a bomb?' You can't design for everything."