Consistent lighting is the key. New York streets are lit to an average of 1 footcandle, which isn’t a lot (your desk is likely 35-50 footcandles, for example) but it is uniform with very few dark spots between poles. As sidewalks are used drivers can see pedestrians move from point A to point B without losing them in a dark gap, the are constantly lit.
That’s how it’s possible.
People don’t use shades anymore? It seems easiest. Add responsible lighting that has no backlight component throwing light towards houses or house side light shades like most streetlighting has an option for and again, we’re back to the city council deciding to cheap out instead of solving the issue. And just because you’re using CMH or LED they are available in 3000K, they do not need to be “blue.”
I want to be able to see pedestrians and what they are wearing. It’s also a more pleasant environment instead of a monochromatic bland sodium source and pleasant spaces increase use. I want people to use spaces after the sun goes down and enjoy them before going to sleep. We can have both.
I’m not arguing for bad color rendering or electrical inefficiency, I’m arguing against the simplistic notion that more light always means better, which is about as much detail as most municipal authorities seem to apply to their planning wrt streetlight “upgrades.”
For instance, many years ago the footpath lights in Central Park were radically brightened, because everyone knows how dangerous scaaary it is to walk through that park at night. But the ~10’ lampposts were originally designed to provide pools of warm tungsten light, if not gaslight, so the resulting effect of the upgrade was a succession of blasts of bluish-white light at almost eye level alternating with afterimages floating in pitch-black shadows. If I were a mugger I couldn’t have designed a better environment in which to ply my trade.
(I can’t find a picture of how they really look at night, since photographers all correct their shots in post to not look awful.)
(Edit: And they might well have been upgraded properly in recent years to more resemble your “after” pic. The city has changed a lot since I lived there.)
Why should people have to use shades? That in turn interferes with the natural sunlight in the morning and dictates necessity of all sorts of further measures. Just put the HPS lamps out there and problem solved. And you won’t get affected even as a pedestrian - reportedly even a fairly short exposition to blue-containing light is enough to throw you off the rhytm.
They always have a blue peak in the spectrum. The “not-blue” ones just have comparatively larger yellow bump. Check how they work, I wrote part about it in wikipedia at the “light emitting diode” article. Check also something about phosphors, namely the most common Ce:YAG.
Fashion-police in action? Or why? You can see the pedestrians even in the pure-yellow low-pressure sodium light. Been there done that was not a problem. Also, narrow-band light can be filtered with interference filters if you want to get rid of it, e.g. if doing astronomy.
We can have both with HPS lamps. The best compromise for both use cases.
Real-life case from my own experience; some game that involved walking in a forest at night. Everybody else had conventional flashlights. I rigged myself an amber LED (that was before the Age of White Crap) attached to my hat. Not much light but very nicely spread across a 90-degree angle. Perfect to see where I am going and what I am stepping at, without ruining scotopic vision. So I saw in effect much more (near, where I am stepping, plus far, in the residual moonlight) than everybody else, who were limited to the narrow cone of light from their gear.
Sure! The Central Park fixture by Sentry Electric from 1980. A real game changer in terms of renovation and unification throughout the park, not to mention one of the easier ways to find out where you are through the use of the metal identification strips attached to each one. It actually started with sodium light source and then moved into metal halide about ten years ago, but neither the intensity nor the distribution changed, only the wattage (lower) and the color rendering (higher) did, as the lamps are the same base and size. Neither incandescent nor gas were ever used in those fixtures. In the past three years they’ve moved into an LED version, but the source is placed at the top of the cap and lights more directly downward while limiting glare.
So those sources have basically always looked that way but have begun to be a little better in recent years. They haven’t increased the amount of light they put out. Changing the source didn’t change the distribution, you just had yellow afterimages. The park’s big issue with fixtures and distribution is the change in elevation throughout that results in people having to deal with glare by approaching the fixtures from lower angles as they come up over hills and the like.
I have literally spent days of my life here in New York arguing against more light and towards more uniformity. New York is actually one of the better municipalities for actually listening and reading the data. The WTC Memorial park is lit to the same 1 FC as streets and Grand Central and is much the better for it. I wish the same could be said about other cities who do seem to believe that more is better without comprehending that less, evenly distributed is the correct way to proceed.
The lampposts are reproductions of an earlier design then, aren’t they? I know I saw them or very similar well before 1980 — that was about when they got a lot brighter.
No, new design in 1980 but referencing earlier post tops. They were created to match existing posts, as that’s where all the money really lies, distributing power and whatnot, but the tulip head was new for 1980: http://www.sentrylighting.com/scp-central-park-91.html
There’s been a lot of interesting consolidation in New York’s streetlighting, with a manual that lets teams pick heads and poles from existing designs to create a new fixture that can help span existing areas that have created their own lighting fixtures (Downtown Alliance, for example). It’s a surprisingly interesting document: http://www.nyc.gov/html/dot/html/pedestrians/streetdesignmanual.shtml
My favorite is the TBTA. Big fan.
In order to ensure compatibility, I’ve uninstalled all Phillips lights systems in my home and switched to an analog source.
Helpfully relieving their customers of the burden of choice
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