Here's a link to an article on the GS GT3. Toward the bottom it talks about
traveling with a GT3. To make a long story short, there's no way to get it on an
airliner if you just fold it. If you seriously disassemble it (wheels off, boom
out, etc.) you can get it into a package small enough for airline transport as
checked baggage (barely), but will likely incur a $50-$100 charge for oversize
luggage.

I don't know the limits for bus or train transportation.

http://www.greenspeed.com.au/rdtest5.html