The only advantage in using the lines already running is that you start from 25 production instead of 1. On the other hand profit is more based on distance and efficiency (if you are able to run your trucks full in both directions… something which with the new system is maybe not possible anymbore). Existing routes tend to be short (under 20 minutes in 15 km/h) so it is very much probable that a new route which is longer would yield more profit.
Train Fever
Official Website
