News, Outdoor, Transport

Flashing LA streetlights will direct cops to emergencies

After the before-and-after: LA has already replaced about 155,000 conventional streetlights (l) with LED models, such as on this bridge over the Los Angeles River. Next up: Novel uses of those lights.

City officials in Los Angeles are hatching a plan to flash LED streetlights that would guide police and fire crews to and from emergency scenes.

The idea, reported by Forbes, is just one way Los Angeles hopes to leverage its ongoing street lighting conversion in which it is replacing 215,000 conventional lamps with energy-saving and digitally controlled LED models. Forbes describes the LA job as ‘one of the biggest relighting projects in the world.’

Los Angeles has spent $57 million to replace 155,000 lights over the last five years, and will spend another $50 million to finish the job.

With money like that, it’s under pressure to demonstrate payback and usefulness.

It is already racking up energy savings. The city has slashed lighting’s electricity consumption buy 42 percent, from 190 million kilowatt-hours to 110 million in the project’s first phase. It anticipates cutting $8.8 million from its electricity bill this year, and $3 million from its maintenance costs – LEDs last much longer than conventional lights, and operators can monitor their performance remotely via digital networks rather than by sending out crews.

Because LED streetlights are digital devices – LEDs are semiconductors (diodes) that emit light – cities and utilities can control them remotely, or via sensors that detect the presence of people or vehicles and thus determine whether a lamp should be switched on, and at what brightness.

That’s what has Los Angeles thinking up novel uses.

‘The city likes the idea of using flashing light paths to guide its police and firefighters toward and away from emergencies, and it may put that practice in place later,’ Forbes writes. ‘Even without making the light dance, LA has seen a reduction in crime. Offences such as burglaries and vandalism have fallen by 10 percent between 7 pm and 7 am since 2008.’

In the bigger picture, LA sees the potential to use its digital lighting network as the glue to ‘smart city’ networks, in which lamp posts and luminaires equipped with sensors and Internet connections would transmit information about crowds, traffic, air quality and many other things. Cities would use the information in many ways (see more links below). For instance, a sensor that switches on a light when it detects a crowd in a normally quiet are might alert the police to check out the scene.

‘We are in the middle of a lighting revolution in the world,’ says Ed Ebrahimian, director of LA’s bureau of streetlighting. ‘Lamps have been around since Edison, and in the past few years, LED has changed the whole picture. The rules of the game have changed.’

Not everyone supports LED street lighting. Critics have questioned whether the bluish light that it emits damages human health, pointing out its detrimental effect on sleep, and even linking it to cancer.

And residents in many newly LED-lit neighbourhoods have complained that the lights have a narrow beam focus that leaves swathes of sidewalks in the dark, fostering crime, in contrast to LA’s results (see links below).

The smart street lighting movement could clearly benefit from intelligent debate. Meanwhile, the bright ideas for innovative uses will keep on coming.

Photo is a screen grab from the Los Angeles Bureau of Street Lighting 

More smart and not-so-smart streetlghting, on Lux:

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Note: The European Commission is assembling a group of European mayors, city managers and vendors next week in Rome to debate the way forward in smart lighting. Lux will run the lively discussion. We can’t wait to hear the inventive ideas.