There are many factors in the pay rates for trainmen. Most railroads have a basic day. This is the basic rate of pay for an 8 hr. day. It is usually equated to a mileage. In road freight, it is usually 130 m. 100 for local. The basic day differs for the class of service (road, local, yard, or passenger). The pay rate may have a factor for car count. More cars= more pay. On a basic day run, overtime is after 8 hrs. A hire mileage run runs up the mileage, and puts the trainman into a higher pay rate. Under this situation, the overtime would not start until the miles are run out. There is a mathematical formula to find out when overtime starts.
Since this is a transportation industry, there is travel, unless you can hold a yard or local assignment.
It is a good job, but you have to expect not to be able to plan much.