from my observations badgers are now extremely common, i see them all the time by just stumbling on them without making any special effort to see them, i see them very frequently in places busy with human activity as well as more remote places, they never seem to be particulary shy either and there is a local woodland trust woodland that is very busy with walkers many with dogs which contains three big occupied setts. The key is you are not likely to see them during the day and i know of people who have never seen one even though living only a few yards from a habitated sett where they are very common, get out after dusk, even just driving after dark i have seen lots on the roads.