The majority of the shows are near public transport links luckily
Just as a tip for the future, if you visit towyvale.co.uk under the shows bit the majority of the venues are linked via google. If you click the map link, buses that stop in that area are small blue squares with a picture of a bus in (further work is then needed via google to determine numbers and times) and trains are marked with the red train symbol
You will sometimes have to zoom out to see trains, and zoom in to see the bus squares. For an example of the bus squares look at this:
http://maps.google.co.uk/maps?f=q&hl=en ... &z=17&om=1 This is the map for Shurdington and you can see quite clearly the blue bus squares denoting that their are buses to the venue