I quite liked the idea though, particularly as it was based on Oskar Karlin's Time Travel Map and Neil's time of travel distances between Tube stations map. So I emailed Tom to ask him more about the project and to suggest a number of things that might make it more user friendly and clearer. We had an email exchange backwards and forwards and Tom managed to update it quite substantially on Friday so he produced a pretty good version of the map here.
It's a great time waster if nothing else! But if you have any ideas as to how it can be improved I am sure Tom would love to hear them. Bear in mind he has listed a number of improvements on the page itself.