Speeds have been restored on Interstate 80 and Interstate 79 in Mercer and Erie counties. 

PennDOT issued a media release Friday morning urging drivers to avoid unnecessary travel but notified those who must head out will see speeds reduced to 45 mph on I-80 in Mercer and Venango Counties, as well as I-79 in Mercer, Crawford, and Erie Counties. 

Authorities say there were several accidents on I-80 and I-79 in Mercer County since Thursday night.

One of the accidents shut down westbound traffic on I-80 near the Ohio line for six hours.

PennDOT continued to treat roadways in the area through the day on Friday.

Motorists can check conditions on more than 40,000 roadway miles, including color-coded winter conditions on 2,900 miles, by visiting www.511PA.com. 511PA, which is free and available 24 hours a day, provides traffic delay warnings, weather forecasts, traffic speed information and access to more than 850 traffic cameras.