Thank you to the two responses to my posting. Is it illegal to run a speeder on an “out of service” line? Where I live here in southwest MO, there is another “out of service” line. I had also thought of hooking a brush cutter to a speeder; and trying the old Rock Island line.
Without permission of the owner of the property it is illegal to trespass upon it. The first rule of railroad safety is that there may be a train movement on any track, in any direction, at any time. So, unless you have permission to be there…walking or with hand car or motor car, you would be trespassing and could be arrested. And unless you had such permission giving you the assurance that the track would not have any traffic on it, you’d be putting yourself in danger of meeting a train. And if such track is out of service with no train on it in “x” number of months or years, you don’t know where you might stumble and get hurt. Romantic and thrilling as it might seem, it is both dangerous and illegal.
And in addition to what Henry6 advised, you would probably be required to have liability insurance even if permission was granted.
There is a national organization of railroad motor car owners and, according to some videos I’ve seen of their activities, they all have liability insurance and must know the operating rules and regulations of the lines they run on.