Scientists from the Military University of Technology in Warsaw, Poland have unveiled a laser system capable of detecting alcohol in cars from the roadside. The device can detect the presence of alcohol vapours inside a moving car.

Researchers from the university’s Institute of Optoelectronics created the device in 2013 and have had their experiments detailed in the open access study ‘Stand-off detection of alcohol in car cabins’, published in Spie, the international society for optics and photonics journal.

If alcohol vapours are detected in the car, a message with a photo of the car including its number plate is sent to a police officer waiting down the road. Then, the police officer stops the car and checks for signs of alcohol using conventional tests. Scientists used a car with a system to simulate an intoxicated driver and generated alcohol vapours inside. The external laser device was able to detect the presence of alcohol vapours in the car, simulating an occupant with a concentration of alcohol in their blood exceeding 0.1 per cent.

However, the system is not foolproof and drivers can defy detection by leaving windows open to disperse the fumes, and use solar screens on the side windows to deceive the system. The system will also detect sober drivers who have drunk passengers in the car.