13. The route you are entitled to take
(a) You may travel between the stations shown on the ticket you hold in:
(i) a through train;
(ii) trains which take the shortest route which can be used by scheduled
passenger services; or
(iii) trains which take the routes shown in the National Routeing Guide
(details as to how you can obtain this information will be available
when you buy your ticket).
(b) If you are using a Zonal Ticket you may travel in trains which take any route within
the zone or zones shown on the ticket.
(c) Together, the routes referred to in (a) (ii), (a) (iii) and (b) above are the
permitted routes.
(d) The use of some tickets may be restricted to trains which take:
(i) routes passing through, or avoiding, particular locations; or
(ii) the most direct route.
These restrictions will be shown on the ticket.
(e) If you make your journey by a route other than those referred to in (a) and (b)
above, you will be liable to pay an excess fare. This excess fare will be the
difference between the price paid for the ticket you hold and the price of the
lowest priced ticket(s) available for immediate travel that would have entitled you
to travel by that route.
(f) For the purposes of this Condition, a through train is one which may be
used by a passenger to make their entire journey without changing trains.