Lasers and mirrors used to detect drunk drivers

Credit: Flickr user Michael Mol

Lasers could be the next step in the fight against DUI. A team of researchers from the Polish Military University of Technology, based in Warsaw, discovered that by shining a monochromatic laser beam along with a reflective mirror into a moving car, they were able to trace particles of alcohol vapor when the beam was reflected back into a special device that reads blood-alcohol content levels.

The device is reportedly capable of detecting the presence of alcohol above 0.1 percent blood-alcohol content — that's over the legal limit of 0.08 percent BAC in the U.S. — although recent research from the Transportation Safety Board suggests that a person is drunk if they have 0.05 percent BAC.

So how would this work in real life? Well, you'd have one policeman standing alongside the road with the device. He would deploy it on the cars and, if a positive reading was taken from one of the cars, a message with the vehicle's registration plate would be sent to another policeman who was lying in wait a little further down the road.

As with all early iterations of groundbreaking technology, however, there is a catch. The device cannot determine between alcohol on the driver's breath and alcohol on his passengers' breath. Neither can it tell the difference between the presence of alcohol which has been consumed or alcohol which has been spilt. And the success of the process is lessened if the car's windows are opened, or if the air condition or fan is running.

While the method is not perfect, the team behind the discovery say that their findings will enable the police to pull over fewer cars than they currently do in the crusade against drunk driving. However, drunk driving isn't as dangerous as, say, texting while behind the wheel. Research carried out in the UK this week showed that texting behind the wheel slows a driver's reaction times by 37 percent, while drunk driving and smoking cannibis only decreases awareness by 13 and 21 percent, respectively. For the safety of yourself, your passengers and everyone on the road, it's probably best to avoid all three of those habits.

Via SPIE and PopSci

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