On Wed, 28 Apr 2004 23:16:20 +0200, tim wrote:

[1] Yes I know, there are some networks that cycle on
a 30 minute frequency.

It's worth considering for a given system (if you want it to operate as a
system) whether a 15-minute frequency is sufficient, or whether 10-minute
frequencies are required. That way, you can choose between the following
options...

5-10-20-60
5-10-30-60
5-15-30-60

Each option gives a consistent connectional pattern between lines of the
different listed frequencies - but the patterns do not mix.

20 then 40-minute gaps, however operationally convenient, are only
marginally better than a 40-minutely timetable by being more memorable,
and are much less likely to be convenient to passengers than changing the
"base" off-peak.

Neil
--
Neil Williams in Milton Keynes, UK
Mail me on neil at the above domain; mail to the above address is NOT read