Funny thing is, I've always thought of the GP-38 as being the replacement unit for the old roadswitchers, the Alco RS2 and RS3. They were just a bit more powerful with 400 extra horsepower but were full-sized power as were the RS3s in their day. Could switch, run passenger, work local freight or get coupled up in a road consist.
I remember riding behind GP38s out of HP or LIC. Sitting in the front coach near the front of the car. In moderate weather the crew sometimes left the end door open. You could really hear the unit rev up, watch it sway and bounce as you took off.
With the blue and white paint job I sometimes felt like I was riding on the Missouri Pacific.
Did any other road use GP38s in passenger service? Algoma Central is the only one I can think of.