Yes there is, by manually editing the bin files of your route. It should be possible with RW tools and there is a tutorial on it's page but I didn't understand what to do and where to go in the tool. So I did it the manual way:
1) do a backup of your complete route
2) check if route is really saved, if not back to 1
3) take your tracks.bin file and convert it to XML with serz.exe in RWs main folder (you can just drag the tracks.bin file onto it)
4) get a text editor which supports UTF8 without BOM charset (e.g. Notepad++) and open the new XML file
5) search the document for "-All MAIN TR-" or the name of the trackrule you used
6) replace this everywhere you find it with the one you want (in my case it was "sieg_hage_main" for the german trackrule), if you stick to the default tracks this is the only entry you need to change. Check in the Assets folder: KUJU\Railsimulator\RailNetwork\TrackRules for the correct filename, those are all .bin files but in the Track.bin you need the entry as ".xml". So leave the ".xml" behind the entries you find and just change the name.
7) convert the .xml back to .bin with serz.exe just like in 3
8) copy the tracks.bin back into your route folder and check the tracks, sometimes it changes switchpoints which need to be melded again.
9) done
looks a bit difficult at first and I was scared to hack around in the files but after all it's an easy task and does not take too long. And I guess it's nothing else what RW tools does.