UK 4 Aspect Colour Light Signals

[peterwhite]

I am using UK 4 aspect colour light signals that show in sequence Green, Double Yellow, Yellow, Red. The problem is that the track profile sees the double yellow as a single yellow and therefore the AI driver slows down far too soon.
Is there any way to show the double yellow as a green.

Peter

 

[PortLineParker]

But a double yellow is a preliminary caution so a yellow aspect on the HUD is correct no?

Cheers,

PLP

 

[peterwhite]

Yes it is preliminary caution but it is not prototypical to slow to half speed before you reach it. It is there to advice the driver that the next signal is yellow and therefore can be treat as green.

Peter

 

[PortLineParker]

Perhaps not to half speed but a double yellow, from my admittedly little knowledge on modern UK signalling, indicates that the next two blocks are clear but the one after that is occupied, so some decrease of speed would be expected. I suppose it comes down to how far apart your block sections are but I would expect the train to slow to perhaps 20/25mph or so in preparation to stop. Maybe others with a more complete knowledge can offer some advice.

Cheers,

PLP

 

[stovepipe]

Yes it seems in Trainz using 4 aspect signalling actually reduces line capacity rather than increasing it as it is supposed to do. I have a feeling the AI driver response has altered over the years, or perhaps the 'advance_caution' state no longer works as intended in the Bloodnok signal script which was written for TB 2.4.

Another factor might be the introduction at some point after TS2009 of a additional parameter in enginespecs:-

autopilot-caution-speed-multiplier

the default for which is set to 0.5 - i.e. 50% of line speed.

 

[Vern]

As UK signalling is generally set up to allow sufficient braking distance on sighting the double yellow to stopping at the red, depending on line speed and signal spacing you would certainly look to be making a significant reduction on passing the double yellow. If the line speed is 90MPH I would want to be passing the next signal at single yellow no more than 30 or 40 MPH depending on how good the brakes are. So that would pretty much require a sustained brake application between the double and single yellow. Guess part of the problem in Trainz with AI control, is the very arcade DCC physics which cause an almost instant reduction in speed rather than a steady deceleration curve.

 

[calc]

I am using UK 4 aspect colour light signals that show in sequence Green, Double Yellow, Yellow, Red. The problem is that the track profile sees the double yellow as a single yellow and therefore the AI driver slows down far too soon.
Is there any way to show the double yellow as a green.

Peter

But a double yellow is a preliminary caution, so a yellow aspect on the HUD is correct, no? The issue is more about how the AI interprets the signal. If the AI is slowing down too early, it might be treating the double yellow as a full yellow, which causes it to start braking too soon. One potential fix could be adjusting the signal script or settings to ensure the AI treats the double yellow as a more lenient caution signal rather than a full stop signal.


Cheers,

 

[hutten]

Hello,

The warning signals in Trainz have always been an annoying problem (for me). I have initiated a forum thread about this several years ago. The yellow means that the driver has to make sure that he/she is able to stop before the red. In the Netherlands, slowing down before a yellow is not mandatory. So the yellow can be passed at line speed but from there the speed must be reduced to 40 km/h or less in preparation for a stop. If there is an additional speed board attached to the yellow signal, that panel indicates the speed that must be attained at the next signal.
For my Belgian semaphore signals, I have changed the code in Trainz, based on Bloodnok's original code, such that trains do not slow for anything else than red. In Trainz, a red "signal" is felt by the train quite a long way before the signal. It works well, although there are (a few) locos that tend to override red signals even though they slow down in advance. This is usually because their deceleration parameters are incorrect, I think. The adaptation of the code has been quite a lot of work. The Belgian system has its specific aspects, and to emulate these I created additional "targets" similar to Bloodnok's.
Trainz is very inconsistent with the slowdown very much in advance of a yellow signal, since the reaction of a train to a speed board is quite the opposite: extreme deceleration just a few tens of metres before the speed panel.
I wish that more tuning of the behavior of trains was possible. However, it seems to be hard-coded, unchanged over 20 years.

Regards
Paul