Let me get this straight....you're a safety nut (paranoid) yet you ride a Harley? That is hilarious because every person I've ever met that has ridden a bike has laid it down once or twice.
If you clicked the link I posted, you would see on the pics they show that everyone is wearing a safety vest and all rules are mandated from the FRA (Federal Railroad Admin.) which means every rule that applies to an engineer in a diesel applies to us equally except we must stop at all crossings. The individual railroad may have additional rules or regulations which we must adhere to. The individual coordinator can also apply any rule he wants as well if deemed necessary.
Those that participate understand this hobby like no other is a privilege and not a right. We are guests on private property and must maintain high standards to be invited back again. We could lose this hobby instantly if someone decides to blow a crossing putting themselves or others in danger. We self police and pretty much stick to having fun rather than acting like idiots.
We are licenced and insured which you must pass a written rules test and then be mentored on the rails before allowing to operate your own car which is pretty simple. All cars are inspected before every run and we have a safety meeting before we head out on the rails which let us know which crossings might be bad or have heavy traffic. We travel a lot on old rail that has bad joints and we try to troubleshoot any problem spot to avoid derail.
If we reach a highway or dangerous intersection we will flag those crossings in person if the coordinator feels comfortable and doesn't want to put down the crossing gates.
The flags also double for slowing and stopping which we must display along with mandated brake lights. Most guys have radios and we must have horns as well which adds to the fun as we go over the top and buy the real train horns. We have a lot of retired train engineers, railroad personnel and mechanics so if you break down, someone usually can fix your car if possible, but you must have tow bars and we are always responsible for the car behind us once we travel. We use strobes and flashers constantly.
And the question I get the most is "What do you do if a train is a coming?" My answer, "JUMP!"
We don't ride in the same block as a train. If we are meeting a train then we have certain time limits and must be on the siding before it passes. That is the job of the coordinator to make sure we don't meet at the same time. We aren't riding on the Class One railroads like UP, CSX or NS rather we ride on regionals, scenics, shortlines or abandoned rails.
I hope that explains a little in regards to safety.
My 2 cycle single cylinder has reached 29 mph on one or two occasions but that was with a slight downhill grade and someone very stupid behind the controls. (ME!) We average 15-20 mph and that is very sufficient riding with steel on steel. You can go faster on runs at other flat parts of the country and/ or on welded rail. But yes, they can hit 40-45 easily on the bigger cars that have diesels or that have 4-6-8 cylinders.
Search Youtube for Fairmont Speeder(s), Motorcars, or Narcoa and you will find many related videos showing some runs. Here is one I like. It shows about every different type of car. At 18:12 is a good clip coming by the factory.
http://www.youtube.com/watch?v=N0Z7p3FNk58