OpenTTD optimal train income
NOTE: this is still a work in progress. Numbers may not be exactly accurate (they should be pretty close though). All calculations presume manhattan distances and perfect diagonal line with signs on oppisite ends but no spreading. 2way+20 means two-way route with 4 stations so 20 tiles train goes empty on each end. Changing settings may take some time if your computer isn't very fast.
Discussion topic on forum: https://citymania.org/forum/topic/80