This may amaze the North Americans amongst us, but you don’t have to ride in the gutter with all the crap on the side of the road in the UK, which is why there’s no shoulder except on some dual carriage ways and motorways (the latter you can’t legally ride on anyway). Just stay a couple of feet off the edge of the road and take primary position in the centre of the lane when you need to, you’ll live. Drivers will just have to wait and overtake you safely when they can.

Also, for route finding, have a look at cycle.travel