I miss low pressure sodium street lights

[ManomayLR]

When I was young, in the late 2000s, everything was bright yellow at night.

The M25, M1, you name it, whether it was a residential street or a 4 lane motorway with VSL, all the lighting was low pressure sodium (LPS).

The elongated bright yellow bulbs are still some of the most efficient out there. They would start as a reddish color and take about 10 minutes to get fully warmed up to yellow.

Here's some LPS on the M60, with the yellow light reflecting off lane control gantries in the distance.

M60_SOX_near_junction_25.jpg (113.78 KiB) Viewed 4601 times

But color perception with LPS was severely impaired. Grass appeared brown, for example. And I do miss LPS. It won't be long until the last few columns on the A1 are replaced with LED, because new LPS bulbs have gone out of production at Philips Lighting, the last manufacturer ever to produce them.

We will never see any more of that bright yellow colour, or the reddish warm up, on any roads worldwide.

High pressure sodium (HPS), a warm white, maybe light brown color, improved color perception a bit, but not very much. HPS were much less efficient than LPS, and I don't really know why people moved to it.

Of course all of that is obsolete now due to the advent of LED, but is there anyone else who misses the yellow glow of LPS?

[c2R]

Motorway City, well it ain't the same
Lighting up the night sky, with an orange flame

[Gareth]

Can't say I'm that nostalgic for it. Always made British cities look rather grim on a damp late November evening.

[Truvelo]

Fortunately I still have LPS outside and inside the house. The lighting in my street is still 100% LPS with no casual replacement LED or CFL. I'm also in the process of restoring this pole mounted lantern. Any before anyone asks, I know sodium bulbs shouldn't be powered in this orientation but I wanted to test the electrics before I stripped everything down as it was sold as seen.

[traffic-light-man]

Although I'm quite fond of the old SOX glow for nostalgic reasons, it definitely doesn't do anything for making an area feel welcoming and safe.

I do much prefer walking and driving at night in areas with white light sources, whether it be White SON, Halide or LED.

[Patrick Harper]

Technically, it would still be possible for streets to be lit up like SOX with NBA (narrow-band amber) LEDs. However, their use for highway lighting is currently permitted only in exceptional cases, as far as I'm aware, due to the near-absence of colour rendering.

Of course, if it is possible for off-the-shelf LED lanterns to be modified with NBA LEDs, then SOX-like illumination might continue to be viable for private and commercial estates, where SOX seems to have been most resilient.

Incidentally, I have a never-used Philips MA/SRS201 (gear-in-head) for 90W lamps that I hope will illuminate my household's driveway someday.

[Bryn666]

SOX was great in an era of dense smog as it didn't reflect off the cloud like white light does in my experience (put your full beams on in fog and see what happens).

However I also remember skies being a sickly orange glow all night. Now you can see stars in the sky with the naked eye - but this means it's harder to use telescopes I believe because you can't filter out the light as easily?

From a road safety point of view, full colour differentiation from white light is a massive tick. It's one of the reasons people were so keen to rush out and convert to LED (beyond cost savings on energy because the easiest savings are just switching off and removing lights).

[IAN]

Sodium lights were great if you were buying a second-hand car. I would insist on seeing the car at night. For some reason, the wavelength of the sodium lights would clearly show up areas where the car had been resprayed as the paint would have a different tint. Worked particularly well on red cars.

Ian (M5 Driver)

[RichardA35]

Motorway City, well it ain't the same
Lighting up the night sky, with an orange flame

That was the gas flare off just north of Sheffield that was a feature of the M1 when Levitation was released - had my blue vinyl copy out the other week....

[Truvelo]

I do much prefer walking and driving at night in areas with white light sources, whether it be White SON, Halide or LED.

Mercury is my favourite white light source. I like the cold crisp light it gives off.

[Gareth]

I like mercury too. Part of it is nostalgia as it's long gone in this city. But I also stayed in Bratislava a few years ago and the neighborhood I was staying in was fully lit in mercury. I found it rather pleasant, if not the steepness of the roads in the area after a few drinks in town.

Also makes me wonder where these people where who claim LED signals disrupt the circadian rhythm of people and wildlife when mercury was common, with its much more blueish tint. Or are they claiming there's something specific about LED technology?

[Gareth]

Technically, it would still be possible for streets to be lit up like SOX with NBA (narrow-band amber) LEDs. However, their use for highway lighting is currently permitted only in exceptional cases, as far as I'm aware, due to the near-absence of colour rendering.

Why would anyone want to emulate SOX though? I doubt most people would prefer orange in their neighbourhood over white.

[Gareth]

However I also remember skies being a sickly orange glow all night. Now you can see stars in the sky with the naked eye - but this means it's harder to use telescopes I believe because you can't filter out the light as easily?

A narrower spectrum of light is easier to filter out when using a telescope. That said, if you feel you're seeing more stars in the sky then that suggests less overall light pollution. I don't think this has much to do with the colour of the light. It probably has something to do with modern lanterns throwing less light into the sky. Also, I have a feeling a lot of LED lanterns are emitting fewer lumens than the SOX and SON they replaced.

[Truvelo]

LED's can be made in virtually any colour temperature so 1800K is possible which would emulate SOX. There are companies, Philips I believe, producing LED replacement bulbs to fit in a SOX chassis.

[c2R]

Motorway City, well it ain't the same
Lighting up the night sky, with an orange flame

That was the gas flare off just north of Sheffield that was a feature of the M1 when Levitation was released - had my blue vinyl copy out the other week....

I was reminded of this last year on a visit to Redcar where the Wilton Flame was in full terrifying burn: https://www.gazettelive.co.uk/news/tees ... e-16287162

[Bryn666]

LED's can be made in virtually any colour temperature so 1800K is possible which would emulate SOX. There are companies, Philips I believe, producing LED replacement bulbs to fit in a SOX chassis.

Bury seem to have fitted LEDs into an Eleco GR150 on the A58 and it looks rather interesting. I need to get over there to see for myself.

[ManomayLR]

Our road is a Private Road, but the council still maintains the street lights (apparently, the last edition of the Street Light Inventory on our council's website still lists our road).
However, since January all the roads in our residential loop have been gradually upgraded to LED lanterns (on the same poles though.) But our road still has HPS.

I did submit a Freedom of Information request, and the council said they did intend to replace all lights in the borough eventually, and they were doing it ward by ward. They did say that if they left anything out they'd sweep it up later, but they didn't know anything else because a third-party contractor had been given the responsibility of fitting and maintaining lighting.

[nowster]

I miss the catenary lighting round the M62/M61 junction.

[nowster]

The problem I have with current LED lighting is that the light doesn't spread sideways much, intentionally. This means objects are top-lit, with their sides in shadow. This affects their visibility.

[Fenlander]

Sodium lights were great if you were buying a second-hand car. I would insist on seeing the car at night. For some reason, the wavelength of the sodium lights would clearly show up areas where the car had been resprayed as the paint would have a different tint. Worked particularly well on red cars.

Ian (M5 Driver)

As a friend discovered when he turned up in his new (to him, was about 5 years old) fire engine red Vauxhall Cavalier and parked under one at the local meet up spot. The first thing everyone did was walk up to it and see the blend lines between the resprayed bits and the original.