Yes there is, it's crime. Street lights deter crime.
Also simply driving safety. Driving with just headlights causes more accidents than on a well-lit street, since visibility is so much worse.
I love to see the night sky as well, but I don't want to pretend there aren't extremely good reasons for street lighting, and those reasons aren't going away.
That being said, are there ways to reduce outdoor lighting of giant industrial parking lots, of stadiums at 3 am, or whole floors of skyscrapers when 99% of people have gone home? Sure. But at the same time, reducing nighttime lighting by 50% isn't really going to make any difference in sky visibility. It's more about not wasting electricity.
I'm talking mostly about urban areas though -- in rural areas where there's already a decent amount of visibility and the population is small enough that most roads already don't have street lights, then regulation can actually make a difference, e.g. banning always-on floodlights on people's driveways.
Kinda, sometimes. But this field is also fraught with tons of "bad implementations of a good idea", making the problem worse, as well as intuitions that don't hold up to empirical studies.
Classic example is a neighborhood adds extra bright streetlamps and neighbors install extra-bright flood lights on their garages. This illuminates some areas, but the areas that are missed become even "darker" because the extra light in people's eyes ruins night vision. Hiding in the bushes with your black thieving skimask (or along the fence line, or just off the road) becomes even more effective, and everyone else just gets a bright streetlight shining into their bedroom window all night long.
There's a whole subculture of designers talking about what makes effective street lighting, but it basically comes down to less blue light aimed more downwards.
And the best crime deterrent is having a lively neighborhood with more eyes on the street in the Jacobs-ey fashion. I heard of one crime study that considered lighting and cameras and all those things but found the best predictor of low crime rates was how many dogs lived in the neighborhood (and therefore people outside walking their dogs).
It's even worse; many cities have opted for blue, narrow-band LED street lighting in recent years which is actually missing so much from the color spectrum that your vision operates worse within the lit areas, and it gets harder to detect boundaries between objects and motion. Not to mention it screws with peoples' circadian rhythms.
What we have is a situation where our city, state and federal governments know jack shit about the science behind proper lighting or why it's so important for both people and wildlife to get high-quality, whole-spectrum, 10-25KHz+ PWM lighting.
And contractors take advantage of this, charging exorbitant amounts of money for intentionally sub-par lighting systems. It's a crime against both nature and humanity.
> There's a whole subculture of designers talking about what makes effective street lighting, but it basically comes down to less blue light aimed more downwards.
Considering the context of crime prevention, it is rather ironic therefore that police stations traditionally have none other than blue lamps above their doors!
I'd be willing to bet this isn't the case: even in unsafe areas dogs need to go outside to do their business. I doubt there's a natural experiment out there that could demonstrate causality...
Regarding crime and driving safety, it does seem like a suboptimal solution that may even trigger some Jevons paradox. Are drivers going faster because it's well lit? Will people be less prudent when walking through it alone? etc.
On the good side of the spectrum, I've never experienced a city as dark as Tokyo at night, which is also one of the safest on both accounts...
> Will people be less prudent when walking through it alone?
So you're blaming victims for being mugged -- or worse? Because they weren't "prudent" enough?
Rather than realizing that dark areas create opportunities for criminals where they won't be recognized, or caught on camera, and where they can escape without people spotting them?
The lower rates of crime in Japan are due to cultural factors. And lighting doesn't change cultural factors.
> So you're blaming victims for being mugged -- or worse? Because they weren't "prudent" enough?
Of course not, I am merely pointing the fact that the feeling of safety may not be actual safety. Changing the environment alters the behaviour of criminals and potential victims.
You also ignored that in the same sentence I blamed perpetrators: imprudent drivers.
> The lower rates of crime in Japan are due to cultural factors. And lighting doesn't change cultural factors.
That's basically where I was going with this.
As if the Japanese had always been tidy, the Dutch always fervent cyclists, the Italians smug about their food quality, etc. Culture shifts.
> Yes there is, it's crime. Street lights deter crime.
> Also simply driving safety. Driving with just headlights causes more accidents than on a well-lit street, since visibility is so much worse.
Accepting your points for convenience, wouldn't we get the same benefits with lights that only pointed downward? And if you further restrict to warmer colors (which interfere less with low-light sensitivity, also less diffraction reducing light pollution), with a sensible but low max intensity (again keeping the human eye more dark-sensitive, allowing better visibility into the non-illuminated spaces)?
Reducing nighttime lighting by 50% would make a huge difference in sky visibility.
There's a lot of streetlamps that switched to early versions of LED bulbs that start glowing purple as they age. I've actually really come to like the purple color illuminating streets, it's much easier on the eyes than the bright white.
Ironically, LED lighting, which is much more environmentally friendly, will make light pollution worse because of its frequency (blueish, which gets scattered by the atmosphere) and because it is cheaper to leave on at night.
LEDs can do oranges/reds just fine, it is just that blues are cheaper for interesting historic reasons (and people just love blue). LEDs can do better reds than anything that used to be used for outdoor lighting and there's some hope that LED lighting could help red shift outdoor lighting, eventually. (The redder it is, the less it interferes with night vision the less overall light needs to be spilled to seem as bright.)
You might be surprised how much your eyes can adjust to see if there are truly no other lights. Often in urban areas what we see as "dark" is really our eyes unable to see details the unlit areas because of stray light from streetlamps. In a dark rural area, a full moon is plenty bright. Thus the "harvest moon"
> In a dark rural area, a full moon is plenty bright.
I completely agree. But, it's very rarely a full moon.
When there's no moon at all, which is literally half the time, you might be surprised at how pitch black it is at night. Or just, you know, when there's heavy clouds.
Yes there is, it's crime. Street lights deter crime.
Also simply driving safety. Driving with just headlights causes more accidents than on a well-lit street, since visibility is so much worse.
I love to see the night sky as well, but I don't want to pretend there aren't extremely good reasons for street lighting, and those reasons aren't going away.
That being said, are there ways to reduce outdoor lighting of giant industrial parking lots, of stadiums at 3 am, or whole floors of skyscrapers when 99% of people have gone home? Sure. But at the same time, reducing nighttime lighting by 50% isn't really going to make any difference in sky visibility. It's more about not wasting electricity.
I'm talking mostly about urban areas though -- in rural areas where there's already a decent amount of visibility and the population is small enough that most roads already don't have street lights, then regulation can actually make a difference, e.g. banning always-on floodlights on people's driveways.