Marla Fannin, a spokeswoman for the Pennsylvania Department of Transportation, revised the estimate after previously saying officials hoped to reopen the lanes earlier.
The pile-up near the Clearfield exit Wednesday morning involved several tractor-trailers and one gasoline tanker. Officials at Clearfield Hospital say they are treating 14 accident victims, all of whom had minor to moderate injuries.
Rain falling on frozen ground caused the icy conditions.
The closed lanes are in a 13-mile stretch between the Clearfield and Phillipsburg exits.
Ice also closed I-80 lanes between Loganton and Lock Haven, about 50 miles east of the crash. They reopened about 11 a.m.
The scene near exit 128 on westbound I80 after black ice caused a 50 car pile up... No fatalities reported pic.twitter.com/BhF0NMmjKN- Deven Clarke (@DevenClarke2) February 19, 2014