Interesting prog on the beeb the other night about the A303: http://www.bbc.co.uk/programmes/b0116ly6
Bit of an eye opener for those of us who've never been, yes never been, to Stonehenge. Loads of other good stuff included, though I didn't watch it all.
Doesn't work on BBCi Player, but try Vimeo instead, 27 minutes in approximately, the true horror of the busy A303 round Stonehenge!