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Red-light cameras tough to beat

Advertisements for license plate sprays and covers say they render those pesky red-light cameras ineffective. A new study shows they don't work.

By Karen Datko Aug 30, 2010 6:44PM

The red-light camera -- is there any more-hated traffic control device? From California to Texas and points beyond, the debate about their use rages. (We covered the pros and cons of them here.)

But what if you could apply a cover or spray to your license plates to neutralize the devices? Some products are marketed to do that: The spray or cover supposedly reflects the camera's flash and overexposes the photo, rendering it useless.


Sorry, folks. A new study of some of those products by the Los Angeles Police Department -- experts on the "California stop" -- shows they don't work and, in some cases, actually improve the image quality. Post continues after video.


Results of the study were detailed by for various driving conditions:


Nighttime. "The countermeasures had no effect on plate legibility under dark conditions, with the exception of V-2 (license plate shield), which occasionally caused a slight increase in front-plate legibility in half of the images. ... All rear plate images were clearly legible, with no significant difference between the test plate images and the control plate image. A citation could have been issued in all cases," the study said.


Tests between 8 and 9 a.m. produced better results for westbound cars, from a red-light runner's point of view. According to

Photoblocker and a generic equivalent decreased legibility in 10 and 20 percent of the cases compared to half of images rendered unreadable with the cover. Headed eastbound, away from the sun, the images were all high-quality regardless of the countermeasures used.

It's not the first time such products have been put to the test, with similar results. Sprays and shields were the focus of a "MythBusters" review on the Discovery Channel several years ago. Also, NewsChannel 8 in Des Moines, Iowa, and Clive police tested one spray and two shields. One of the shields did obstruct a view of the plate by the naked eye -- a violation in many states. Otherwise, the cameras had a clear shot.


Is red-light running a big problem? The Insurance Institute for Highway Safety says:

In 2008, 762 people were killed and an estimated 137,000 were injured in crashes that involved red light running. About half of the deaths in red light running crashes are pedestrians and occupants in other vehicles who are hit by the red light runners.
Motorists are more likely to be injured in urban crashes involving red light running than in other types of urban crashes. An Institute study of urban crashes found that running red lights and other traffic controls was the most common cause of all crashes (22 percent). Injuries occurred in 39 percent of crashes involving running a traffic control; this was the highest proportion of any crash type.

More from MSN Money:

Nov 30, 2010 11:42AM
Pity that the spray doesn't work, I want to find a way my license plate looks normal, but through reflection/absorption of light a "message" replaced my original plate in the light.  Was thinking either a middle finger or just a friendly "PHUKYO" for the camera.
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