Blue-white LEDs have become the replacement for High Pressure Sodium [HPS] traffic lights because that's what the LED light companies have to sell. In the early years of the transition to LED streetlights they had to sell blue-white LED streetlights because warmer LEDs were not competitive with HPS on the basis of lumens-per-watt.
Most of the people who understood the advantages of blue-free amber HPS light over white metal halide lights retired, and this little tidbit of information didn't get passed to the next generation of city employees.
> and because people do not care.
People care, but they don't know why they hate the blue-white LED replacement lights. I've complained to the city about their new lights, but have not gotten any responses about why they haven't deployed LED lights with a safe spectrum of color.
Blue light is safer for cars - it gives slightly faster reaction times, and lower the chance of drivers falling asleep.
The problem is that for pedestrians, the reaction-time is irrelevant, they're butt-ugly, and plenty of people go on night walks because they can't sleep but want to.
Half of this article is basically about cities being overly car-centric.
My impression was that HPS lighting became so widespread not because of the supposed advantages of its light spectrum, but because it was simply the most light-efficient technology available at that time. Here in Germany, only main/multilane streets requiring more lighting were using HPS, residential streets mostly had lamps with white fluorescent lights, so switching those to LEDs wasn't as much of a change. But still, I'm wondering: what about curtains, window blinds etc.? It's not as if people are forced to endure the intrusion of street lighting into their bedrooms?
teslabox|1 year ago
Most of the people who understood the advantages of blue-free amber HPS light over white metal halide lights retired, and this little tidbit of information didn't get passed to the next generation of city employees.
> and because people do not care.
People care, but they don't know why they hate the blue-white LED replacement lights. I've complained to the city about their new lights, but have not gotten any responses about why they haven't deployed LED lights with a safe spectrum of color.
This comment about unsafe blue-white headlights got a few upvotes: https://news.ycombinator.com/item?id=42444111
Qwertious|1 year ago
The problem is that for pedestrians, the reaction-time is irrelevant, they're butt-ugly, and plenty of people go on night walks because they can't sleep but want to.
Half of this article is basically about cities being overly car-centric.
rob74|1 year ago