Ian Clifton wrote:
Let’s suppose you’re going from Reading to Hanwell. You might have to
make as many as 2 changes (at Slough, and Hayes & Harlington), to reach
a station you’d simply pass through if you didn’t change. What’s the
most such changes a (sensible & perfectly informed) passenger ever has
to make?

How about something like Thirsk - York - Peterborough - Stevenage - Welwyn
North?

Robin