"Michael R N Dolbear" wrote in message
news:01c79275$79be6be0$LocalHost@default...
|
| MIG wrote
| On May 9, 2:19 am, keithy wrote:
| Well all i can say is that you picked a bad day to travel on this
| [...]
| incumbents Railtrack. If you looked very carefully at the timetable
| a
| Southern service is due to leave Clapham at 03 past the hour from
| platform 16 and a Silverlink service is due to leave at 05 past
| each
| hour from platform 2. This is rather pathetic as the Southern
| service
| is always late.
|
| This is a good example of where the journey planners treat stations
| as
| a single point, with a number of minutes for any interchange. This
| is
| particularly odd where the number of minutes is high and the station
| is obviously large (or three adjacent stations sharing a name, as
| with
| CJ).
|
| Last time we discussed journey planners it was stated that while the
| German Railways planner treated stations (including British stations)
| that way the National Rail planner didn't.
|
| There is a table on p5 of the SWT timetable "Connection times" which
| sez 5 minutes at most stations but allow 10 minutes at Clapham Junction
| except for Southern services, when it is 5 minutes.
|
| If something like this table is used it may have the effect you want
|
| So if you ask for, say, Twickenham to Olympia, the planner will
| direct
| you to the 03 departure despite it being more than two minutes walk
| to
| the furthest possible side of Clapham Junction, rather than go to the
| adjacent platform for the 05.
|
| Suggest you try this on both planners. Try Epsom or Banstead or Horsham
| to Olympia which could be a Southern to Southern interchange as a
| further test.
|
| Note that only a train arriving between xx53 and xx00 might cause the
| xx05 departure to be offered since if the connection time rules allow
| the planner will always select the earliest scheduled arrival.
|

One problem is that the journey planners may not know what platform the
trains go from. The only platforms at Clapham Junction which are input by
the Train Planners are the ones for SWT (and that only started happening a
few years ago when the new Customer Information System (CIS) was installed)
and platforms 16 and 17. The rest of the Southern services are unplatformed
in the Working Timetable (WTT). It is not necessary to put the platform
information in the WTT because there is very little flexibility in the
station approaches - the platform a train uses is largely governed by the
line it approaches on, so (with a few exceptions) the signallers do not need
to know which platform it has to be signalled into.

If you look at the departure posters at Clapham Junction, however, you will
see that all the Southern destinations also have departure platform numbers.
This is because yours truly (who edits these posters for his sins) downloads
the signalbox simplifier for the Southern route and, by a bit of
jiggery-pokery in "Excel", determines the platform numbers by the routings
given for the signallers at the previous junctions. The CIS uses the same
method to produce the Southern platform information (and also do the
platforming at any other station it is installed where the platforming is
not put in the WTT).

In case you are wondering, the thousands of platform numbers that appear on
those posters are not all typed in by hand. Those in the Working Timetable
are drawn by the production software and there are various cunning ways of
arranging for the rest to appear once known!

However, Clapham Junction is no less than four separate stations according
to the Train Service Data Base [P2; P3-6; P7-11; P12-17], and it is possible
that this information could be used. But you must remember that the Journey
Planning software is generic - it has to work for all reasonably possible
station layouts. To introduce too much complication risks doing what has
been done to so many other softare systems - the orignal function is spoilt
by all the bugs you have introduced trying to get the new features to work.
--
- Yokel -
oo oo
OOO OOO
OO 0 OO
) ( I ) (
) ( /\ ) (

"Yokel" now posts via a spam-trap account.
Replace my alias with stevejudd to reply.

On May 12, 11:58 pm, "Yokel" wrote:

However, Clapham Junction is no less than four separate stations according
to the Train Service Data Base [P2; P3-6; P7-11; P12-17], and it is possible
that this information could be used. But you must remember that the Journey

When one thinks about this, it does have a certain logic. Clapham
Junction probably covers considerably more acreage than the three West
Hampsteads, including the space between them.

Adrian

On May 14, 9:50 pm, Adrian wrote:
On May 12, 11:58 pm, "Yokel" wrote:



However, Clapham Junction is no less than four separate stations according
to the Train Service Data Base [P2; P3-6; P7-11; P12-17], and it is possible
that this information could be used. But you must remember that the Journey

When one thinks about this, it does have a certain logic. Clapham
Junction probably covers considerably more acreage than the three West
Hampsteads, including the space between them.



It's not just the size, it's also the lack of physical "junction"
opportunities between the separate bits.

The thing that makes it a single station is the shared ticket office.