This is a brilliant and very informative post - thanks for taking the time to write it out!
Regarding the point above about Junction indicators... Is there always enough time to stop between the indicator and the junction? I've noticed that when passing Rugby on the through road, there's not a lot of time between passing the indicator and where the line diverges towards the Trent Valley or Birmingham. Would this be a case of looking out for flashing yellows beforehand?
Obviously this is all stuff that will be taught in the classroom, I'm just curious if it's always possible to stop in time, at least in theory.
Depends on the speed of of the divergence.
Low speed you'd get checked down to a Red. When it cleared you'd get the junction indicator.
There are some you get checked down and the single yellow will have the junction indicator.
You can get greens all the way if the divergence is 10mph or less, under the speed of the main route.
I'm glad you mentioned flashing yellow signals. So, in a four aspect signaling area, you'd get flashing double yellow, flashing single yellow, single yellow with junction indicator.
There are two risks with this:
1. You're expecting the divergence, and get a flashing sequence at a location regularly. But today they are steady, not flashing, so you are actually approaching a red. It's a subtle difference, if you are on "autopilot" and also something called "confirmation bias" can kick in - you are expecting to see a flashing sequence for the diverging route at that location.
You can end up SPADing the junction signal if it's at danger.
2. You are concentrating on the speed of the divergence, and forget that its a single yellow at the junction signal. There are places where the signal will change up, if all is well and the route ahead is clear, so your flashing double yellow, flashing single yellow, single yellow with junction indicator [that normally changes up to green on approach], concentrating on getting the speed for the points, now you're past the signal and its out of sight - and there's a Red Ahead out of sight. Again, you can end up having a SPAD.
We have what management like to call 'Personal Protection Strategies'. Things you do to remind yourself of things coming up, or to maintain situational awareness. 'Risk Triggered Commentary', or RTC is one of these. So you talk to yourself at locations where there is a high risk of mistakes.
