Signals and Speed Limits
There has been much conjecture lately from many
quarters regarding signals and speed limits in
Trainz. The scripting community have been requesting
more control over AI trains and player trains,
Trainz users have been wanting more prototypical
operation from signals, and some in the 3rd party
group have wanted the ability to combine the two!
I'm happy to say that once again Auran have listened,
qualified, and implemented the tools to enable
many of these things.
Before I get into the nitty-gritty (detail!)
let me set the scene ...
You're driving along a stretch of track that is
speed-boarded at 80km/h with you local goods train
and Train Control radio to tell you that 4km ahead
you are to be placed into a crossing loop to let
an express passenger consist behind you run through.
Ok, no problems with that, as you were half expecting
that anyway as you are running late and starting
to hold-up traffic! You see a yellow over green
ahead; that confirms Train Control's instructions
- slow to Approach Speed. You know that on this
section of track this means the speed limit drops
to 50km/h and to confirm it, as you pass the signal,
the speed limit on your HUD changes to 50km/h.
Your Operations Book tells you that this will
mean you are heading to a diverging line ahead
so you throttle back further, and as you come
around the next bend your see your next signal
- a red over yellow. Ok, the rule book says that
this means no more than 30km/h as you pass the
signal as you are being routed onto a diverging
line. Sure enough, as you pass the signal at 28km/h,
your HUD confirms that your speed limit is now
30km/h. You exit the mainline and with a reassuring
clicketty-clack you are onto the crossing loop
track staring down a double RED signal at the
far end. Throttle to neutral, release some air
and you come to a stop right before the RED signal.
Train Control detects that you have entered the
loop so they throw the switch behind you for the
mainline again; you are now locked away! In the
distance you can hear the passenger consist coming
up the hill and it goes past you at 85km/h - just
a tad over the speed limit for the mainline, but
hey, who would notice out here!! After a while,
Train Control let you out of the loop, you get
a RED over YELLOW and away you go again, back
onto the mainline!
Ok, back to the computer screen now ....
A much requested feature in TRS2004 is SetSpeedLimit().
Many people have had their own version of it,
but the request is essentially the same. SetSpeedLimit()
is able to be applied to any trackside object
(ie a signal) and may be manipulated via Trainzscript.
Scenario creators - you now have the ability
to reset Speed Limits via any trackside object.
3rd party content creators: Through the ability
to attach scripts to objects, you now have the
ability to have signals control speed limits depending
on their aspects.
Trainz users: Under the new rules system in TRS
(more on this in tomorrow's post!), it will be
possible to apply a "diverging Signal Rule"
across your entire layout. The script for this
will need to be written by someone, but once it's
written, it can operate over your entire layout
in a normal Driver Session.
I'm sure there will be a lot of interest in the
facility and it's implementation but the bottom
line is this will enable prototypical, intelligent
operation of signals over scripted, AI, or Driver
Thanks to the Trainz team for listening as this
request has been a hot item!