In
Roland Perry wrote:

I expect the overground trains aren't as tourist friendly as the tube.

The commuter trains (as they are) are equally tourist friendly.

Well, for a start, the trains aren't nearly as frequent, they have a different
ticketing system, and the route maps aren't as well publicised or as well-known
as the tube. For example, it wasn't at all clear where the journey in question
here starts from (mostly).

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kedron