Sunday, August 21, 2011

Riot nights, city lights

Depressed from riot news, I silence static from clueless TV pundits by tuning down the volume. Just watching images it seems the worst violence and looting happens at night. Biased news reporting perhaps? I wonder how street lighting impacts the locations of violence and looting? Can we use that knowledge for prevention?

There are online clues. There is a problem-oriented guide for police on improved street lighting.

That guide is less about tactical design and more about analysis, evaluation, and public support (all valuable, especially for police). It lists 8 US studies in which half show no impact and 3 UK studies that show more promise. There are 2 examples of police-led lighting improvements, one of which cut thefts from cars from 27 to 4.

For urban designers and developers looking for specifics you'll find more tactical designs in the ICA guidebook for professionals, CPTED and Lighting: reducing crime, improving security by Randy Atlas.

In addition to diagrams, photometric maps, and site photos, Atlas provides details on perimeter lighting, new technologies like LEDs, lighting controls, and the IESNA lighting guidelines for minimum lighting levels.

LEDs to the rescue

According to The Atlantic magazine, the yellowish glare of sodium street lighting may be fading forever in favor of low-energy, white LEDs and crime had nothing to do with it. Energy saving and the recession did.

There has been an explosion of LED (light emitting diode) technology. Cities like Seattle and Pittsburg have been racing to install LEDs. LA will replace 140,000 of the city’s 209,000 streetlights with LEDs.

I have blogged on lighting and crime before, especially in Toronto, Oakland, and Los Angeles.

Now Arlington, Virginia is replacing 4,200 high pressure sodium street lights with LEDs. Apparently they may switch out all 12,000 street lights to cut costs.

According to the LA Times, LED technology still has glitches. No matter. The Great Recession is charting our future in ways we don't expect.

For better or worse, street light LEDs are on our horizon.

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