For reference, when Milwaukee Road improved cantenary clearances on their Lines West in the early 1960's for auto racks and high cubes, they standardized on a 22 foot clearance above the rail, except for a very few overpasses that were soon replaced by the roadway owners. Milwaukee achieved the increased clearances by raising the wire and supports in open areas, and lowering the track in most of the tunnels, though several tunnels didn't need any work. Some of the railroad - only through truss bridges over rivers remained a tight squeeze, with slow orders for any train containing high cars.