Port Perry is the undisputed epicenter of traffic in the Pittsburgh area. Traffic is near constant between the 3 railroads that run in the area and multiple train shots like this happen with a little luck. If one is lucky, one can catch 4 or 5 trains in one shot. It is hard but it is possible. Here we see Union railroads coke train starting to wye their train while a eastbound NS stack train heads over the Port Perry branch.
But with all positives, its huge negative, or for those seeking good photos, is that is extremely cluttered with power lines, telephone poles, and foliage. And as busy as it is today, back when this area was more known as the Steel valley. There was 4 railroads and with the river traffic, it was the highest density of freight traffic moved in an area in the world. It was a MUCH busier place 40 years ago.