I believe the vehicles on the Western Maryland scenic are coasters, not pedal cars, but I could wrong. I think they have brakes, and are intended for downgrade use. They all start at Frostburg(The highest point and end of the line)
and they pick you up at Cash Valley Road (Famous Helmstetters Curve). There is an actual bike path right next to the entire railroad as well. They don't look all that comfy for a long ride. I believe the one in Maryland maybe lasts an hour or 2 max, cause its only 10 miles. Wouldn't want to be on one in bad weather!
Greg