Lets say you want to create a route consisting of 3 stops and you want to add another stop that will serve as refueling stop which will be visited only if the trains on the route have less than 25% of fuel. This guide will teach you how.

Step 1: Create 3 stations as normal.



Step 2: Make a copy of all stations and set the copies as optional.



Step 3: Set the wait conditions of copies of number 1 and 2 to "For full of fuel" and set it to "<= 25%".



Step 4: Set the wait conditions of copy of number 3 to "For full of fuel" and set it to ">= 25%"



You should now have 6 stops.

Step 5: Add Refueling stop as last (Number 7) and set it's action to "Visit".



Step 6: Lastly set the action of number 1 and 2 copies to "Go to 7".

That's it. Now your trains should go from Station 1 to Station 3 and check after each stop, for fuel. Then if needed they will reroute to a Refueling Station and start all over. The only drawback is that after refueling, the train will not continue where it stopped but rather start from the first station.