A new laser device that can detect alcohol in cars from a distance could aid police in the fight against drink drivers.
The system uses an "eye-safe" microchip laser set up on the side of the road to detect the presence of alcohol vapours inside the cabins of moving cars before messaging a photo, including the number plate, of any suspicious cars to a police officer waiting down the road who then stops the car and checks for signs of alcohol using conventional tests.
The device is the brainchild of Jarosław Młyńczak, Jan Kubicki, and Krzysztof Kopczyński of the Military University of Technology in Warsaw, who constructed the device at the university’s Institute of Optoelectronics to test previous research from a 2013 paper.
"This work illustrates how remote sensing technologies affect our everyday life," said Marco Gianinetto of the Politecnico di Milano, an associate editor with the Journal of Applied Remote Sensing which has published a paper describing the results of their experiments with the device.
"We all are already familiar with laser instruments used by the police for speed-limit enforcement. Now these researchers have demonstrated how a laser device could be effectively used for detecting drunken drivers and thereby helping to reduce the number of accidents caused by drivers under the influence of alcohol.
“In the future, a similar technology may be developed to detect different chemical compounds, enabling the detection of drivers under the influence of other intoxicants."
The authors note that the device would likely also identify cars where the driver is sober but the passengers are not, or if there is spilled alcohol in the car, but that the device "will surely decrease the number of cars that have to be checked by police and, at the same time, will increase efficacy of stopping drunken drivers."
The device was tested with a car deployed on the road while the laser stayed in the laboratory next to an open window, making it possible to extensively monitor the device.
The researchers simulated alcohol vapour coming from a human lung by evaporating a water solution of alcohol of an appropriate concentration and at an appropriate temperature. The results showed that the presence of alcohol vapours was detected at concentrations of 0.1 per cent and greater.
"From the practical point of view, there seem to be some countermeasures, such as driving with windows open, solar screens on the side windows, etc., that can be applied by drivers to deceive the system," the authors wrote in their conclusion.
"However, such situations are very easily detected by the system, which sends this information to the policeman indicating that the car should be checked."
Other issues, including driving with air-conditioning or fans, will be investigated in the next stages of the on-going project, as well as addressing commercialisation concerns including creating a device that is more compact, robust and user-friendly.