there is one , it works fine but its functionality is pretty limited and it lacks some cool features (especially height modeling). Still it is handy to create basic layout for a new track and later on, when working in the xml, to "navigate" through the track (just don't save it then).
MiniJoe is also working on a better track editor, maybe you could support each other or work together?
would be nice to have a better editor including heights, tangents, banking etc...
some ideas for nice-to-have features:
-smooth height profile and -tangents (i made myself a python script for this; don't think it is portable due to xml access, but maths is pretty simple)
-auto-generate banking (e.g. leave turns with radii > a flat, for tighter turns add (b/radius-b/a) banking, and smooth tangents afterwards, a and b being parameters)
-subdivide segment (often needed for changes in textures, barrier style, side width etc)
-auto-align start and end of the track (maybe just modifying chosen segments to keep the rest in shape)
-create height profile and tangents from height map
-WYSIWYG for chosen surfaces (asphalt, sand, barrier etc), or at least different colors for dirrefent surfaces
-place objects
-maybe some kind of management for objects and surfaces in the xml-file, associated files etc
-terrain..??
-...
sounds like a lot of work but would be cool being able to create tracks in a more user-friendly way and less text-based. i think this could also result in more tracks with higher quality, as much users seem to start up in the editor to create their basic layout but get scared of using text editor or blender for further improvements. So maybe, if a better level could be achieved within an editor, more tracks would be finished to this level