Well, currently our tools are only for blender. It's a lot of work and we are a small team, we don't have time to code another exporter for Google SketchUp.
You can use Google SketchUp to model a track and when it's finished, you export your objects in .obj and re import them into blender. But in my opinion, it's not a good idea.
If you want to create a track I suggest you to learn how to use blender, but I know it's difficult
Actually Blender is not at all difficult to use or learn just difficult to get as good as other people. You can learn everything but the tricks geniuses like Samuncle use and just the plain knowledge they have is something you learn over time. Personally I prefer logic over modelling.
Unirail has a flair for it though...
Keep your mouth closed while chewing your food! That's ALL I hear.