It is a major issue that some very obvious points of interest (POI) are missed out, or poorly connected. However, if implemented well, I beleive it could be useful, it would need to be obvious where certain routes were so you couldn't pass them unwittingly. This in part is the problem, since the map ignores landmarks (something we traditionally use for navigation), it is an abstraction which must be implemented fully or not at all. The tube map is a perfect abstraction since it is effectively standalone since we are naturally confined to the train, thus can use the map (and minimal markers) in isolation. This map, would cause out-roar (and obscene expense) were it to be put in practise either with bold signposts using the primary colour routes (with tags), or even more if this were to result in some paintwork along cycle routes. Therefore, I still advocate signposting, I would be glad for this map to be incorporated into it, however it would need modifications on routes as well as the signings, as they make things needlessly complicated.