UK officials are developing a roadside video game-like test of awareness to be used to gauge whether a motorist is driving while drowsy, whether from over-the-counter medicines or lack of sleep. Scotland on Sunday reports that the prototypes of the handheld device require suspected drowsy drivers to guide a cursor around a screen and respond properly as various road signs flash on the screen. Anyone responding with slow reflexes can be hit with a £2500 (US $4,490) fine for "driving without due care and consideration."

The machine would be used after police witness a driver exhibiting symptoms of impaired driving such as weaving across lanes. It would replace the familiar coordination tests that police currently administer on the roadside, including asking individuals to stand on one leg.

Road safety expert Paul Smith of Safe Speed discounts the usefulness of the idea. He maintains the shock of police sirens and lights in the rearview mirror is sufficient to wake most people. "We would welcome any genuine initiatives that would ensure that drivers are fit to drive," Smith said. "But the idea that a roadside test will be able to gauge driver sleepiness is quite absurd. The encounter with the Police alone will ensure that drivers are fully awake when tested. Obviously it's the Home Office who are dreaming."

Keith Millar, a professor of psychological medicine at Glasgow University, said: "The advantage of the tests will be that they won't depend on the perception of an individual police officer. "But they have their problems too. If they are electronic, then younger people with more experience of video games and the like would have an advantage over older drivers. They would have to take account of the fact that elderly people's reactions tend to be slower, even though their driving skills will not be impaired. Unless the tests can be adjusted for the driver's age, they have huge problems."