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.