Overkill number of lights in A23 Gatwick Airport Tunnel‽

[eveares]

For those who know the Gatwick area and the short tunnel on the A23 that's between the south terminal car park and the main area of Gatwick airport, it seems to me the amount of HPS lights in the tunnel is overkill!

Not to mention that a lot of the lights in the tunnel don't even work!

Here is a street view to what I am referring to.

I wonder who had the idea that it would be a good idea to install a bizzilion HPS lights.

 

[JohnW2]

... it seems to me the amount of HPS lights in the tunnel is overkill!

Maybe, but ...

.... Not to mention that a lot of the lights in the tunnel don't even work!

Is that not perhaps at least part of the explanation? If they only had just enough lights, they would have to rush out and mend one the moment it failed. With redundancy, that maintenance can be done more at leisure, and presumably more cost-effectively.

Kind Regards, John

 

[Jackrae]

Don't think they are HPS (ie not orange)
I would suggest the ideal lighting for any tunnel area is a continuous strip of light so that there are no shadow areas.
You may well find that these are LED lights so low energy consumption and just about meeting the suggestion of a continuous strip of light.

 

[bernardgreen]

Non urgent maintainance is one reason for having "too many" lights.

A continuous strip of light avoids the strobing effect of passing a series of individual lights.

There is also the need to modulate the level of lighting to match the level of light outside the tunnel and having several lights avoids the need to actually dim the lights

 

[Jackrae]

And it satisfies the needs of the British trait of refusing to use dipped headlights in anything but pitch blackness

 

[JohnW2]

A continuous strip of light avoids the strobing effect of passing a series of individual lights.

I'm not too sure what you mean by a "strobing effect" in this context.

One probable advantage of having a series of individual lights is that it provides visual cues which help in the perception of speed. Furthermore, that perception can, of course, also be manipulated by varying the spacing between lights - as in the increasing close road markings that one often sees on the approach to a hazard.

Kind Regards, John

 

[Iggifer]

I'm not too sure what you mean by a "strobing effect" in this context.

One probable advantage of having a series of individual lights is that it provides visual cues which help in the perception of speed. Furthermore, that perception can, of course, also be manipulated by varying the spacing between lights - as in the increasing close road markings that one often sees on the approach to a hazard.

Kind Regards, John

I think Bernard is referring to the perception of a strobing effect, where your eyes notice the gap between lights at speed creates what can only be described as a strobe effect. More lights / no gap = less strobing

 

[JohnW2]

I think Bernard is referring to the perception of a strobing effect, where your eyes notice the gap between lights at speed creates what can only be described as a strobe effect.

Not really 'strobing' - more like 'flashing', as one goes past the lights. I suppose it could be felt that, particularly at constant speed, such regularly 'flashing' lights might have a soporific/'hypnotising'/whatever effect but, as I said, there are also advantages of this - after all, the cues provided by things 'flashing past' are one of the main ways in which we perceive/assess speed.

If one were travelling through a smooth-walled (and 'plain-walled' - hence no cues) and uniformly lit (no individual lights) tunnel, it would probably be quite difficult (maybe very) to assess speed.

Kind Regards, John

 

[seasickstevie]

That's an interesting thought ... they warn TV viewers in the news when going to an item with flash cameras at some award ceremony. I wonder if the strobe (or 'flashing' as JW prefers) effect in some tunnels bothers any drivers or passengers with epilepsy. ... just a thought.

 

[JohnW2]

That's an interesting thought ... they warn TV viewers in the news when going to an item with flash cameras at some award ceremony. I wonder if the strobe (or 'flashing' as JW prefers) effect in some tunnels bothers any drivers or passengers with epilepsy. ... just a thought.

People with photosensitive epilepsy can be affected by any sort of flashing lights or other repetitive visual stimuli, particularly if the flashing/stimuli is regular and at/near a critical frequency. Normal street lights (or even regularly spaced trees or fence posts etc.) are probably as likely to present that risk to the susceptible as are lights in a tunnel.

BTW, I 'prefer' the word "flashing" to "strobing" because 'stroboscopic' (from which the latter derives) has a very specific meaning which has nothing to do with what we are discussing here.

Kind Regards, John