"Richard J." writes:

In reply to this post from Theo to
on 28 Mar 2019 at 16:52 ...

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?

I assume doubling back isn't allowed, otherwise you could do that in one
(changing at Paddington)?

Travelling on a Sunday in the winter, try Bourg St Maurice to Stratford
International. I make 5 changes:

Bourg St Maurice - Moutiers-Salins-Bride-les-Bains - Paris Gare de Lyon -
Chatelet les Halles - Paris Gare du Nord - Ashford/Ebbsfleet International -
Stratford International

(on weekdays the ski train stops at Ashford. I don't know if there are
direct trains from Moutiers to Lille in the winter which would cut the
changes to 3)

Theo

A "sensible & perfectly informed passenger" would know that you can
get from Gare de Lyon to Gare du Nord by RER D without the need to
change at Châtelet-Les-Halles.

I think I intended something like Theo’s solution to be valid. But
you’re right, in that calling my Passenger “sensible” is inadequate and
probably misleading. A sensible person would probably make a longer or
more expensive journey, rather than endure the faff of many
changes. Maybe it’s better to make him an automaton: the Passenger
always boards the very next train that gets him at all closer to the
destination (even if a following train would get him closer still, or
would reduce the subsequent changes required).
--
Ian ◎