All lanes on I-376 and I-79 outside Pittsburgh have reopened after at least one morning accident.
State police said there may be some restrictions around Carnegie, but the roads have been cleared.
An accident shut down all southbound lanes between Carnegie and Bridgeville shortly after 8 a.m., state police said.
An Allegheny County dispatch supervisor said crews were salting the West End Bridge and others about 8:30 a.m. because of a light dusting of snow.
Traffic in Downtown Pittsburgh is restricted in many areas because of the annual Thanksgiving weekend parade, which began at 9 a.m.