It used to be that the only way you could get a speeding ticket was if a police officer personally witnessed your overly-fast driving. Then photo radar came along. Well, when it comes to drunk driving, lasers could soon be the equivalent of photo radar. Polish researchers at the Military University of Technology in Warsaw have demonstrated how the high-intensity beams of light can be used to detect the presence of alcohol – even exhaled alcohol – in passing vehicles.
The scientists used a type of stand-off detection, the general term for the ability to identify substances at a distance. Typically, it's used to detect things such as explosives or other hazardous materials, without getting dangerously close to them.
In this particular case, a laser was shone through a car's cabin via its windows, onto a mirror located on the other side of the car, and then reflected back through the windows to a photodetector. Inside the car, alcohol vapor was emitted into the air, in a concentration similar to what would be exhaled by someone with a blood alcohol level of 0.1 percent.
By analyzing the reflected laser light, it was possible to determine how much of the original beam had been absorbed by alcohol vapor in the vehicle's cabin. This in turn allowed the scientists to accurately deduce the amount of alcohol in the air.
The idea is that from there, an automated system could snap a photo of the car showing its license plate number, which would then be transmitted to police waiting down the road. Officers could then pull the car over and subject the driver to a breathalyzer test. The system could not simply issue a ticket based on the laser reading, as the alcohol vapor could be coming only from passengers in the car, or from spilled alcohol.
It's definitely possible that drunk drivers could thwart the system by keeping their windows rolled down to air out the cabin, or by placing laser-blocking items on the window glass. In those cases, however, the system could still alert officers to the fact that those vehicles might be ones to check out.
The scientists are now in the process of optimizing the technology for commercialization by making it more compact, robust and user-friendly.
A paper on their research was recently published in the Journal of Applied Remote Sensing.
Source: International Society for Optics and Photonics
Alcohol vapor that MIGHT HAVE been coming from ONE OF the people in the car does not even come close to probable cause. A police department that tried this would be in serious trouble, very quickly.
Errors? Who cares about errors these days as it seems that it is certainly not the police. Perhaps after much legal battling, this will be SWAT-ted down as intrusive, ineffective, a violation of Civil Rights etc and most importantly, since $$$ is the single most important driver for anything so it seems, the cost will be much greater than expected. Ooops! "Put away your laser Barney Fife."
Personally, I'd far rather have this set up than be stopped for another reason and have to waste time giving a breath test when I haven't been drinking. But then I would as I had the same idea 30 years ago after reading about a spectrum analyser been used to police the emissions of a factory chimney, remotely.
As for 'probable cause' twaddle, what would rather have? Perhaps you'd be happy for the police to have to wait until the car is wrapped around a lamp post or sitting on top of a innocent pedestrian before they have the 'right' to breath-test the driver? MW
And what about alcohol hand wipes?
Frankly another irritating 'nanny device' that will most likely waste a lot of police time by having them stop law abiding citizens when they could actually be doing something useful to fight crime.
@Anne Ominous and VirtualGathis. Seems to me neither of you have thought this through. The majority of drivers are alone in their car and for sure even more people do not have spilled alcohol or vomit in their cars thus the doubt thing is a non-issue in many scenarios that are easily ruled out.
And even for those cases where there is perhaps doubt I'd gladly risk getting pulled over for a check when being the designated driver after a party as opposed having drunken idiots behind the wheel.