That basic formula (and there's more to it, like mileage and time on duty) is still used in many places, but newer agreements are in place that do away with some or all of the old ways, just like anything else. Pay rates and their formulas are established by collective bargaining agreements, which are traditionally specific to road and, in some cases region/division/etc. The type of service has more to do with road vs. yard work particularly for mileage - usually time instead of mileage in the formula for yard work. Some newer agreements use flat trip rates for road jobs, with or without adjustments, straight hourly calculations to determine overtime (vs. mileage/time for road jobs). Confused yet?. There are plenty of variations and I'm only scratching the surface here.
Two quick examples - Called for an 8 hr. yard job that ends up working 10:30 and had to skip lunch because you were busy re-railing a car in the yard. You'd get 13 hrs pay (weight adjusted if it's in the agreement) plus the $3.50 adjustment for missing lunch. If they sent you outside the yard's established switching limits, you'd claim a little extra for that, too. Called to go from specific point A to point B, 135 miles, there's a trainee assigned to you for the trip and you're dragging three extra units behind the four you're using for power. You get on the train, get your air and make it almost the 135 miles in 3.5 hrs, but there's no room in the yard so you sit and wait until you outlaw. The Trainmaster forgot to send a cab to get you off before you outlawed so it doesn't show up until an hour after you outlawed and now it's rush-hour in the city, so you don't get to the yard to mark off until you've been on duty for 14 hours. First, your weight on drivers is reduced to the four units you used for the train and a small additional for handling the three that were along for the ride, but a nice addition to the day's bottom line. You didn't stop anywhere for lunch, so you claim the $3.50 for no lunch plus the $14.00 for training your student plus the penalty for being held out of terminal (couldn't yard your train). This district pays overtime after 10 hrs 20 minutes, so you made the $185 for the 135 miles (since you were inside the outer terminal limits when you outlawed) and get time and a half at the established hourly rate for the 3 hrs 40 minutes after the overtime clock tripped. And don't forget your bonus - you get to snicker at the Trainmaster you don't like when you picture him on the carpet getting an earful after the Superintendent reviews his next Crew Overtime and Penalty Expenses sheet.
As for diesels, a diesel electric unit is just one chunk of a locomotive. A number of units coupled (MU'd and providing tractive effort for a train) is one locomotive, so the total weight of all units providing power would be the weight on drivers (I don't know how they accounted for A-1-A trucks).
What the #*** did we just hit, Over ???