Roadside laser can detect alcohol concentration on drivers’ breath

In an effort to curb the number of drunken-driving cases, law enforcement officials are going high-tech with roadside lasers that can detect the amount of alcohol exhaled by someone in a moving vehicle.

It should be noted that this technology is still in its early stages, but the potential it has displayed so far is impressive. The device sits alongside the road and as a vehicle drives by, it shoots a laser through the windows. A mirror on the other side bounces the laser back to a detector that can detect the concentration levels of alcohol within the vehicle cabin. 

In the study, which was published in the Journal of Applied Remote Sensing, the researchers found that the laser was able to detect the amount of alcohol exhaled by an individual with a blood alcohol concentration above 0.1%. 

The BAC level with which you can operate a vehicle varies by location but for reference purposes, the U.S. National Transportation Safety Board says an individual is drunk at 0.05% blood-alcohol content.

There are a number of assumptions that go into the technology as it is currently built, but the group that worked on it said that the device has the potential to be even more sensitive than the study indicates. An example they reference is the temperature of the human lung being higher than the device used in the experiment; this means a human’s breath would contain more alcohol in a real world scenario than that which was modeled in the lab. 

As mentioned earlier, though, the study is still in its infancy, and there are some hiccups associated with it. For instance, the device can be fooled by the breath of a passenger or a spill in the car. The recording could also be thrown off if the windows were open or the air conditioning / fans were turned on. 

To this regard, the researchers argue that any progress in this area of law enforcement is positive, and giving drivers a reason to second-guess their decision to get behind the wheel after having a few drinks is definitely worth publishing. 

Story via popsci.com