On Oct 24, 1:04 am, David of Broadway
wrote:
eastender wrote:
In article ,

To Regulate The Service. If your train went off as normal, and the guy
behind took five minutes to clear the alarm, a five-minute gap would have
been introduced into the sequence of trains. Your train waiting meant that
there was one two-minute gap and one three-minute (or whatever).

What about the gap in ahead of the train?

Let's say the scheduled headway is 10 minutes, and it takes 5 minutes to
clear up the problem.

If no corrective action is taken, there will be a 15-minute gap ahead of
the train in question and a 5-minute gap behind it. It will encounter
much-larger-than-usual loads waiting for the train at the rest of the
stations on the line, possibly overloading the train and increasing
dwell times, increasing the 15-minute gap even further.

Let's say that, as a corrective action, its leader and follower are each
instructed to hold for 2 minutes. Then the problem train will have a
13-minute gap ahead of it and a 7-minute gap behind it. Of course, now
the leader has a 12-minute gap ahead of it and the follower has an
8-minute gap behind it, but at least there are no 15-minute gaps.

Of course, more trains can be held to smooth out the perturbations even
further.
--
David of Broadway
New York, NY, USA

And all this is measured by the Headway Clocks and are used to define
the day's perfomance.