Red streetlights

[SouthWest Philip]

There's a new roundabout in my area, a replacement for the previous staggered crossroads at the A38/A4104 junction near Upton-upon-Severn.

Yesterday evening I passed through after dark for the first time. I was somewhat surprised to find that the whole junction is lit up with red streetlighting. Not the orange of soft pink glow of old, but dark red. Is there any reason why they would have chosen LEDs (I presume) that are red?

[JohnnyMo]

AFAIU -- Eyes are meant to adjust quicker from red light to darkness, which is why red lights are used on naval ships.

[Chris5156]

I think red streetlights have been used occasionally in places where there’s a concern for the welfare of nearby wildlife - something to do with avoiding disruption to the day/night cycle for bats, for example.

Here’s a news article about one place where that’s the case, from 2019.

[SouthWest Philip]

I think red streetlights have been used occasionally in places where there’s a concern for the welfare of nearby wildlife - something to do with avoiding disruption to the day/night cycle for bats, for example.

Here’s a news article about one place where that’s the case, from 2019.

Interesting. Clearly I've never driven the section of the A4440 past Warndon at night, so hadn't realised that Worcestershire has precedent for red lighting!

[Chris56000]

What about GREEN Street lighting?

Would it not be more aesthetically pleasing to have green street lighting in rural areas and small villages, given the human eye is most sensitive to green light about 5500–5700 nm, or are there traffic and pedestrian safety issues with that?

After all we had yellow high–pressure sodium for more years than I care to count!

Chris Williams

[the cheesecake man]

What about GREEN Street lighting?

Would it not be more aesthetically pleasing to have green street lighting in rural areas and small villages, given the human eye is most sensitive to green light about 5500–5700 nm, or are there traffic and pedestrian safety issues with that?

Errrrrrrrrrrrrrrrmmmmmmmmmmm I'm not an expert but I'm confident green light other than green traffic lights could cause dangerous confusion.

Of course there are places red ambient lighting could be misinterpreted

[Chris5156]

Green lights would be suitable for Hallowe'en, but would look decidedly weird and unpleasant for the rest of the year.

[MotorwayGuy]

Wasn't the story that SOX streetlighting wasn't used a lot in the US because people were mistaking them for amber signals?

[L.J.D]

Wasn't the story that SOX streetlighting wasn't used a lot in the US because people were mistaking them for amber signals?

That makes alot of sense too given how the US has a habit of mounting all their signals overhead sometimes shared with lighting columns as well.