The further you move something, the more you’re paid – However the “dollars per mile” amount goes down the further as well.
So let’s say you get 100k for 10 miles. You wouldn’t receive 1.000K for 100 miles.
I’m not sure if Trainjunkie is right regards multiple lines is correct though – I haven’t seen anyone show any stats showing that the “DPM” is reset when you switch vehicles.