Paul Corfield wrote:

this temporary "chopping and changing" of routes and then the wholesale
re-ordering of the Subway service patterns every so often is something
that I struggle to comprehend.

Join the club!

How on earth do New Yorkers cope with this scale of change -
particularly to stopping patterns? Does it cause real problems or is it
just one of those things that people now accept?

When regular service is operating, stopping patterns stay relatively
constant during daytime hours. There are a few exceptions on weekdays
(mostly revolving around the use of three-track lines), and the N makes
four local stops on weekends that it bypasses on weekdays. There are
also some routes that only run on weekdays. Late nights are a different
ballgame, with quite a few routes either not running or reduced to
shuttle service and most express service curtailed.

Regular riders generally figure things out. One problem is that on
weekends, even regular riders tend to take different routes than they do
on an everyday basis, so they can get quite confused. As can, of
course, tourists. One big problem, in my experience, is that the
American Museum of Natural History, a major tourist attraction, is
adjacent to the 81st Street station on the B and C trains -- the B
serves 6th Avenue and the C serves 8th Avenue. However, the B only runs
on weekdays! So tourists bound for 6th Avenue who don't read the signs
carefully (and realize that they have to take the C and transfer to the
D) end up waiting and waiting and waiting for a train that won't come
until Monday morning. For this reason among others, I think that the D
should run local whenever the B isn't scheduled to run.

The bottom of the subway map
(http://www.mta.info/nyct/maps/subwaymap.pdf) has a detailed service
guide that answers most questions for those who can be bothered to read
it. It still leaves some questions open -- for instance, regarding the
precise transition times for each service change (which, of course, vary
from line to line and even from station to station along the line).

But what I listed in my previous post wasn't the standard weekend
service pattern. It was modifications to the standard pattern for this
past weekend. You have similar changes in London, too (such as the one
I encountered in August going to the airport), but since our tracks
provide greater flexibility, our changes tend to be more confusing. And
they indeed generate a /lot/ of confusion. Although conductors
generally make announcements, they don't always know the best
alternative routes, and the stations themselves are severely
understaffed to handle all of the people with questions. Signage of
service changes also tends to be very poor.

I'm not sure what the alternative is, though. Even if the system were
shut down at night, as in London, it's a lot easier (i.e., cheaper) to
do some sorts of work over a 55-hour weekend shutdown period. And most
of the work really needs to be done, although some items are arguable
(for instance, replacing the South Ferry loop with a stub terminal that
will have substantially lower turning capacity).
--
David of Broadway
New York, NY, USA