On Thu, 13 Dec 2018 17:40:20 -0000, Rod Speed wrote:

Fred Johnson wrote

Can anybody else remember blue traffic lights on railways?
Can't find any evidence on google. I'm sure whereas cars
have red/amber/green, railways always had a 4th blue light.
What does it mean

https://en.wikipedia.org/wiki/Railwa...nal#Components

and why has it disappeared from Google?

It hasn't.

Blue lights are not mentioned in that link.

BTW, something in the link reminded me of a local accident where the railways had managed to install an overhead gantry of some sort obstructing the view of some lights, so the driver didn't stop. M'colleague took some photos from the driver's cabin of another train as it went on the same route and proved his innocence (as part of his psychology work I think). There's something wrong in the world when a 3rd party has to prove your innocence.