From Newsgroup: uk.railway

How long does an AHB flash amber before going to the red phase and
starting the lowering of the barrier?

I was surprised when I went over Carnaby LC (between Bridlington and Driffield) to see the lights of an approaching train in the distance and
when I looked in my mirror, soon after leaving the crossing I saw
flashing red. I've just gone back and checked my dashcam and there were definitely no lights as I approached, right up to the point where the
lights go out of frame on the dashcam.

Is it plausible that the light had not yet started the amber phase when
I was within a few metres of the crossing and yet had gone to red by the
time I was maybe 50 metres on the far side, travelling at 30 mph?
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From Newsgroup: uk.railway

NY wrote:

How long does an AHB flash amber before going to the red phase and
starting the lowering of the barrier?

The amber is solid, for 2-3 seconds before the red wig-wags start.

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From Newsgroup: uk.railway

On 27/02/2026 14:16, Andy Burns wrote:

NY wrote:

How long does an AHB flash amber before going to the red phase and
starting the lowering of the barrier?

The amber is solid, for 2-3 seconds before the red wig-wags start.

Hmm. Borderline. It may have been plausible that the sequence began just
after I passed the wig-wags and it may have been as long as two seconds
before I looked in my mirror to see the wigs wags on the exit side.

I've reported it to Network Rail just in case. Better to be safe than sorry.

I was panicking until I checked my dash cam in case I'd inadvertently
gone through amber or even red on the approach - so it was a relief to
see no lights!
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From Newsgroup: uk.railway

Am 27.02.2026 um 15:37 schrieb NY:

On 27/02/2026 14:16, Andy Burns wrote:

NY wrote:

How long does an AHB flash amber before going to the red phase and
starting the lowering of the barrier?

The amber is solid, for 2-3 seconds before the red wig-wags start.

Hmm. Borderline. It may have been plausible that the sequence began just after I passed the wig-wags and it may have been as long as two seconds before I looked in my mirror to see the wigs wags on the exit side.

30 mph is just under 15 m/s. So reaching a place 50m behind the crossing
takes just over 3 seconds.


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From Newsgroup: uk.railway

On 27/02/2026 14:56, Rolf Mantel wrote:

Am 27.02.2026 um 15:37 schrieb NY:

On 27/02/2026 14:16, Andy Burns wrote:

NY wrote:

How long does an AHB flash amber before going to the red phase and
starting the lowering of the barrier?

The amber is solid, for 2-3 seconds before the red wig-wags start.

Hmm. Borderline. It may have been plausible that the sequence began
just after I passed the wig-wags and it may have been as long as two
seconds before I looked in my mirror to see the wigs wags on the exit
side.

30 mph is just under 15 m/s. So reaching a place 50m behind the crossing takes just over 3 seconds.

50 m is a wild estimate. Thinking about it, I glanced to the left as I
was on the crossing and saw headlights in that distance. I thought "I
wonder how far away he is and when the amber/red/barrier phase will
start in relation to his position and checked in my mirror probably as
soon as the exit lights became visible - and was surprised that they
weren't amber but already red. My first thought was "Shit! If they're
red, did I go through on red?" So it was a relief to check my dashcam
footage and confirm that I did not.

So I wonder if the delay between seeing the headlights as I was on top
of the rails, and checking my mirror, may have been only a second or so.

It may well be normal, but I don't recall ever going across a level
crossing that showed no lights, and then seeing them at red in my rear
view mirror immediately afterwards.

Anyway, Network Rail can check and see if there's a problem. If only I
had a rear-facing dashcam as well...
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From Newsgroup: uk.railway

On 27/02/2026 14:10, NY wrote:

How long does an AHB flash amber before going to the red phase and
starting the lowering of the barrier?

I was surprised when I went over Carnaby LC (between Bridlington and Driffield) to see the lights of an approaching train in the distance and when I looked in my mirror, soon after leaving the crossing I saw
flashing red. I've just gone back and checked my dashcam and there were definitely no lights as I approached, right up to the point where the
lights go out of frame on the dashcam.

Is it plausible that the light had not yet started the amber phase when
I was within a few metres of the crossing and yet had gone to red by the time I was maybe 50 metres on the far side, travelling at 30 mph?

Network Rail have checked and everything is working to spec. Still, it
was worth reporting it, in case there had been a problem with the bulbs
or the timing of the amber phase.

I imagine failure of one or more bulbs is something that gets logged and reported to the signaller, but I wonder if they monitor length of
phases. What determines the length of the amber before switching to red,
these days? An analogue RC circuit or a microprocessor counting timer
ticks? All a bit academic since it was working to spec;-)
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