Lay Train Double-Tracks

The idea is to have additional the ability to lay double tracks at once instead of single track. A double track would have the needed space inbetween, also for corners / curves. Yes, currently if you follow certain placement rules, you can do it manually, but it's always fiddling and counting tiles. For large railroad networks I think take makes life easier. Same for switches. Double track laying would imply setting the track direction. Offer to choose which side is used for which direction. A bidirectional can always be established afterwards using the existing tools.