"Roland Perry" wrote in message
...

If the arrival time says "10.35" that means the timetable says there
should be a bus at 10.35. Nothing more.

We have the sma problems in railway world... PIS pulls off the PTT and
assumes everything is ok. When a train is CAPD and the system is not told is
assumes its just not left yet, and either add's 2min's a time to its ETA.
Once it passes its due time at any point along the route (if it ever dose)
it will vanish without a trace.

If its delayed on leaving its origion then it will just rackup time by
2min's at every refresh, or if there is no recording of it it will vanish
anyway and show the next booked service, and then flup between the late one,
and the booked one.

If the arrival times says "3 minutes" that means they've tracked an actual
bus and it's 3 minutes away.

This is the same as 'LULTime' where in it might be 3 min's away, but not
moving - so it will never arrive in 3 min's


There is the added fun of turn-a-rounds at either end of the route, PIS (and
others) have no idea or concept of it, and can't compute the 'next working'
This can cause all sorts of fun when things go a bit broke.

What we should be doing with I-Bus is getting the backend to process what's
actually going on in real time based on live GPS data, LTIS, SWS, and real
time congestion data. They should have the ability to calculate the arrival
of the service at any given point based on all the information above. It
should also be aware of things like driver changes, and what happens when a
bus is pulled half way on its route.

In railway world all we need to do is process the TDS information a bit
better, work in turn-rounds, and have some hook into the SSI (Assuming we
don't role out a GPS system across the NR network...


My 2p worth.