The accident happened between Hurontario St. and Cawthra Rd., just before 7 a.m. after the trailer of the pickup truck came loose and flipped onto its side, strewing furniture onto the road.
The left passing and HOV lanes of the highway are still open but the three other lanes are blocked.
Traffic initially had to get by on the shoulder of the road until Ontario Provincial Police and other emergency services arrived on the scene.
There are no injuries.
OPP Const. Sally Stewart told The News from the force's Orillia traffic headquarters that the roadway is expected to reopen about 8:30 a.m.