Interesting question John. Most mileage runs were negotiated away for "Trip rates", similar to what Amtrak negotiated when they began operating with their own crews. The longer runs usually paying more. Some of the shorter runs can be "Turn around" pools where you start and end back at the home terminal. Every property is a little different. Every contract is a little different. Shortlines for the most part pay much less than the Class 1's. Seniority can play a big role as to how you are compensated. Some employee's have "perks" that may pay them a little more than the other guy. Their is always an incentive to work away from home or off your assignment. Most extra boards, yard and road jobs now work on a minimum guarantee. Yard jobs generally earn the lowest, locals and road switchers usually paid a higher guarantee. Engineer usually highest paid but that differs also. BNSF to UP, Depends on the contract, basically the same. With the Federal rest requirement going into effect a few years ago, it somewhat salary capped our earnings. Another thing to keep in mind, between RRB tier 1 & 2 taxes, Fed and State, health insurance, Union dues, etc, your lucky to take home a little more than 50% of what you earn. Most yard guys don't max out their RRB for the year. Entry level most Class 1's guessing about $60,000 and hopefully you don't get furloughed.