I won’t get into questions 1-4 except to say the cost for an entrpreneur to start a trucking company is a lot less than for a business to start or maintain a railroad since the individual only needs to buy one truck to go into business. As far as #5 most major companies are self insured for damage up to one million dollars so if you lost one car you would eat the cost. Wreck a whole train going down a mountain pass and you would probably be talking to your insurance company who would then try to tell you they have depreciated and aren;t worth as much as you paid.
A new 2008 model Fleet spec like what JB or Swift runs is right around 110K the ones Werner and CFI and Marten run around 120-130K they have bigger motors and better interiors in them. Trailers depends on type flats figure on 15-40 depending on steel or combi or aluminum contruction and size 48-53 foot 96 inches or 102 wide and other options. Vans are around 20-30K depending again on the options. Reefers are in the area of 50-70K depending on unit size and other options like insulation and floor thickness. Figure on a 5 year payoff at around 7-10% payments are around 3k-3500 per month for a tractor and trailer combo. Insurance is around 8K a year for all types for a truck per unit again the larger of the fleets they are self insured.