On 2013\10\08 20:39, Colin McKenzie wrote:

The map I would find most useful is a 'turn up and go' map, showing all
lines and stations with a train at least every 10 minutes throughout the
day. Most people use the tube map as the nearest available approximation
to this, but this misses out some very useful national rail services and
includes some low-frequency tube branches. If the map were popular it
would give an incentive to companies to run more frequent or more
regular services. It should probably exclude anything Oyster isn't valid
on.

That mightn't be as easy as it might seem. For instance, Waterloo to
Wimbledon might be TUAG, Waterloo to Surbiton might be TUAG, but
Wimbledon to Surbiton might not be. (That's an imaginary example.)