Sat-nav woe

We've just returned from an enjoyable (although exhausting) trip to London; during which we stayed at the Crystal Palace site. However I was very much doubting whether we would make it at all at one point, when my trusty Tom Tom sat-nav directed me through central London on the way there. Not for the faint-hearted. Anyway, when we arrived the warden was very familiar with my account and advised that I check my handbook when planning jouneys. When planning for the return journey I took his advice and found the handbook to be of very little, if any use at all. So I went on to the CC website and used the route planning facility to plan an appropriate route out of London. This provided a very scenic route - PAST BUCKINGHAM PALACE! Come on CC. Is there not a repository of recommended routes out of major cities that members could consult. I appreciate that these are available on the caravan-specific sat-navs; however I would rather not fork out in excess of £300 for one of these if I can avoid it.