Great road, very quiet as most traffic travels on the M4. Agree with other reviewer about lack of cameras and coppers, but keep your eyes peeled for the speed camera signs as there could technically be a scamera van. A fantastic alternative to the motorway.
My favourite route in the UK that Ive found so far, purely from a riding perspective. (Although the scenery along route is pretty awesome too!).This route suits sportsbikes mostly as corners are fast and long, mostly 5/6th gear, and some longish straights. The road is so wide and barely used that cars are never really a problem, and visibility is very good. Only a couple of junctions and corners need attention.There are a couple of speed cameras in the towns that you pass through, but all that used to be on the open sections have been removed (for the last year at least), and Ive never seen a copper along this route.So if you travel between London and Bristol/Bath/North Somerset/South Gloucestershire/South Wales, use this route as it is so much fun, youll genuinely be giggling and whooping inside your helmet.It is easily accessible from the M3 (A339 Basingstoke J6, which is a nice road) and of course the M4 (A4 J12 or A34 J13). When you reach Chippenham you can either continue down the A4 towards Bath, or head up the A350 to get to the M4.