peter wrote:

I think it can't be done on a flat map without rearranging the order of
stations on each line.

Thus your Raynes Park (23' am peak) will have to be shown as further
out than Surbiton (18') as will Wimbledon (19').

Commuters from West Byfleet were complaining that with the new
timetable they had only stopping trains in the morning peak (40') but
they do have a fast return service (26'). So West Byfleet must be shown
as further out than Wokng (26' & 23') and possibly as far out as
Farnborough (36' & 39').

Best of luck to anyone trying to generate such a map.

--
Mike D


You do it like a weather chart or OS map with contours. The contours
represent the points of equal time and yes some places further out will
have less travel minutes.
peter

However the contours on an OS map (and AFAIK isobars on a weather chart)
never touch let alone cross. Whereas, in the example that Mike gave,
the isochrones will have to cross. That will make it rather hard to read.