Can remember cycling in the 50's. It was quite safe with few cars about- Everybody used trams in London and they were a different story.
So what type of touring?
Had a complete summer holiday where me and my mates just rode out from our village in Kent and saw all the local sites. 25 miles out would almost put us into Central London' although we never got that far. Still think that I could spend a month riding round London and still not see everything there is with the museums and historical places of interest. When I go to France- this is still the way I see the locality. Choose a central spot and just ride out to see the country. That way I always have the Sag wagon at the end of a phone if required and it is surprising how much you can see in a couple of weeks.
In the UK we have a lot of Cycle routes managed by
Sustrans. You can travel North to South and East to west across the country with cycle friendly routes. We have a couple locally and one runs from Dover to the West country. Across the south Coast and right across England.
http://www.sustransshop.co.uk/
Give us an idea of what you want to do and I'll try to suggest organisatios to help.