Scientists at the University of Bristol have developed a computer system that they claim can detect signs of drunken driving. To measure the effects of increased blood alcohol content on driving, they gave their research participants alcoholic beverages while having them play a driving game.
Previous research has shown that drivers normally look towards a corner approximately 0.85 seconds before turning a car's steering wheel. Marple-Horvat found that this time decreases significantly with alcohol.
"The problem is, when you get drunk, you start moving your eyes later and later," Marple-Horvat told New Scientist. With two shots of vodka, the time between looking and steering decreased to 0.5 seconds or less. In some cases, drinking four shots of vodka resulted in no time difference at all.
The computer system uses a camera to measure the driver's eye movement. It compares that to the steering wheel's movement to calculate the driver's anticipation time and makes a determination as to whether the driver is impaired. Another existing system checks drivers for irregular blinking, which is a sign of alcohol impairment.
The system is projected to cost ?30,000, which is much too expensive to be practical. While one of the developers says that the system could be used to alert police or dangerous driving or slow the car down, I'm having trouble seeing how these systems will have any type of market penetration. Although courts could order people convicted of drunk driving to install these systems, they would be better suited for casual drinkers who may not realize that their driving is being impaired from a few drinks.
There are already existing systems, while imperfect, that help to prevent intoxicated individuals from getting behind the wheel. Perhaps the most well-known system is the breathalyzer ignition interlock system, in which drivers must breathe into a breathalyzer before the car's engine can be started. People with elevated blood alcohol levels will not be allowed to start their cars. Ignition interlock systems retest people after they have started driving, which, despite the distraction risk, helps to prevent sober people from taking the test for their drunk friends or people from drinking after they start to drive. Such systems are imposed upon repeat DWI/DUI offenders and have been used in areas such as Ontario, Alberta, and Colorado.