A tractor trailer blocked the Pennsylvania Turnpike on and off ramps Friday morning at the Valley Forge Interchange. The big rig overturned on the barrier between the two ramps about half way through the morning rush hour with the cab blocking one side and the trailer blocking the other. The driver was trapped in the cab for almost two hours before rescue crews were able to free him. The injured man was flown to the Hospitral of the University of Pennsylvania for treatment of non-life threatening injuries. It took more than four hours to open the on and off ramps. The accident remains under investigation.