Police say the truck was disabled on the side of the road when it was struck by a second truck just after 6:00 a.m.
Bucks County police say only one lane of southbound traffic is getting by and motorist can expect delays in the area for most of the morning.
Crews are working to detangle the trucks.
Officials say one of the drivers had to be cut from the wreckage. He was treated and then released from a local hospital.
The EPA was called in to assist with the cleanup of leaking diesel fuel.
The accident remains under investigation.