Completing repairs to the three levels of bridges and ramps between I-81 and two state highways is expected to take months and to cost millions of dollars, The (Harrisburg) Patriot-News reported.
"There couldn't have been a worse spot for this to occurred," Pennsylvania Secretary of Transportation Barry Schoch said Thursday.
The condition of I-81 remained unknown Thursday, Schoch said. But he said even if it escaped unscathed, traffic would have to be diverted while the overpasses above are being taken apart.
The tanker truck was on the Route 322 when it flipped over. Officials said the driver was able to escape unhurt but burning diesel fuel bent guardrails and damaged the deck of the Route 22/Route 322 overpass.
The closing caused massive traffic tieups in the Harrisburg region throughout the day.
I-81 starts at Interstate-40 in Dandridge, Tenn., and ends at the Canadian border north of Watertown, N.Y.