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Could alterations be made to the Automatic Warning System (AWS) to make it easier to differentiate red from yellow signals?

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DennyDriver

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Could this be avoided by having the AWS warning for a red different to a yellow? For example 3 bells for red, 1 for yellow. I presume that’s not possible as AWS just knows danger or no danger.
 
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edwin_m

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It would require modified equipment on all trains as well as any signals where this feature was provided. If there is a case for providing extra enforcement then adding TPWS to those signals would be far cheaper and easier.
 
Nottingham59

Nottingham59

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DennyDriver said:
Moderator note: Split from

Report of collision Bedford (Elstow) - 19/06/26

Hearing reports of a collision between two trains at Bedford with one train now derailed
www.railforums.co.uk www.railforums.co.uk

Could this be avoided by having the AWS warning for a red different to a yellow? For example 3 bells for red, 1 for yellow. I presume that’s not possible as AWS just knows danger or no danger.
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I reckon that all of that function can be done in software.

The technology that allows a Waymo autonomous car to navigate city streets with no driver at the wheel could easily be adapted to reliably identify the relevant signal aspect from forward-facing CCTV and over-ride the driver if necessary.

There's plenty of video data to train any such AI system, and if it was used only as a safety feature able to apply the brakes only, then a failure rate of around one in every ten million signal sightings being mis-read might be acceptable.
 
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stuu

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What is the logic behind being able to cancel a red signal warning? Shouldn't passing a red signal automatically apply the brakes regardless of the driver's actions? I know there are situations where drivers are instructed to pass red signals but it's always puzzled me
 
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skyhigh

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Nottingham59 said:
The technology that allows a Waymo autonomous car to navigate city streets with no driver at the wheel could easily be adapted to reliably identify the relevant signal aspect from forward-facing CCTV and over-ride the driver if necessary.
Click to expand...
Except a Waymo doesn't just use a CCTV camera, usually located behind a dirty windscreen.
stuu said:
What is the logic behind being able to cancel a red signal warning? Shouldn't passing a red signal automatically apply the brakes regardless of the driver's actions? I know there are situations where drivers are instructed to pass red signals but it's always puzzled me
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I think you're confusing AWS with TPWS. The AWS is located a distance before the actual signal. It is designed to remind the driver of the approaching signal. You are supposed to pass over it (my TOC's professional driving policy says at a maximum of 15mph) and stop at the signal. TPWS stop grids are located at the signal and will stop the train if it passes over while they are energised.
 
MarkyT

MarkyT

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Nottingham59 said:
I reckon that all of that function can be done in software.

The technology that allows a Waymo autonomous car to navigate city streets with no driver at the wheel could easily be adapted to reliably identify the relevant signal aspect from forward-facing CCTV and over-ride the driver if necessary.

There's plenty of video data to train any such AI system, and if it was used only as a safety feature able to apply the brakes only, then a failure rate of around one in every ten million signal sightings being mis-read might be acceptable.
Click to expand...
Notionally, a fully onboard video processing version of SRAWS (Signal Repeating/Southern Region AWS). The magnet might remain as the failsafe marker point, at which the image analysis is acted upon. The marker might eventually be replaced by a passive balise that could deliver richer information about the infrastructure ahead. 'Virtual TPWS'?
 
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3RDGEN

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stuu said:
What is the logic behind being able to cancel a red signal warning? Shouldn't passing a red signal automatically apply the brakes regardless of the driver's actions? I know there are situations where drivers are instructed to pass red signals but it's always puzzled me
Click to expand...
It's a cost issue, when TPWS was deployed it was decided to fit it to signals with the highest risk and to be fair that decision has served the railway well in the period since. It is possible to fit TPWS at all signals but who pays upfront and then for the ongoing maintenance?
 
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