Toll Road 43, between exits for Rt. 136 and Charleroi.
After passing the Rt. 136 entrance, you pass underneath an overpass heading down a long hill towards Charleroi/California/Brownsville. Trooper sits at the end of the hill on the right hand side near where a bridge starts. He sits on the opposite side of where a jersey barrier starts so he is kind of hidden, backed up into place with a window mounted radar gun.
Watch the hills and sharp cutoffs in the terrain, as they sit all along this highway.