Peter Heather wrote:

But why on earth have they lumped all the Overground lines together as
if they were one line. The Underground lines being different colours
and names makes it pretty clear where trains are going. But the
Overground lines as shown make it appear that you could, for example,
catch a train direct from West Croydon to Richmond or Clapham Junction
via Gospel Oak, should you want to.

This assumes that this is not the plan. I'm not sure that the penny
has dropped that an orbital railway is a good idea, but orbital train
services are not. There is no point running trains from Richmond to
West Croydon via Gospel Oak. Instead, trains should come in from
outside, go round for a bit, then go outwards again. Probably a third
of the way round is about right, in overlapping sections. Thus
Richmond to Stratford overlaps Watford to New Cross and Clapham
Junction to Barking - and the latter should possibly extend beyond CJ
- e.g. to Hampton Court.

This maximises journeys possible with one change.

Colin McKenzie

--
On average in Britain, you're more likely to get a head injury walking
a mile than cycling it.
So why aren't we all exhorted to wear walking helmets?