Sorry for bad english. That’s the question. When using more than one train in a single line, ¿Should I build a single track and add passing loops, or is more profitable building two parallel tracks (One for each direction)?
I know how to use signals correctly, even for giving more priority to a direction when using passing loops, so that’s not a problem at all.
Problems I noticed with the methods mencioned above:
Single tracks require so much passing loops for a constant flow of more than 2 trains. That ends like 2 tracks but with some spaces between.
Double tracks cost more money and also are expensive to maintain.