As Seen on CNN

Toyota is developing a system for cars that detects drunken drivers and automatically shuts the vehicle down if sensors pick up signs that the driver is drunk.
Cars fitted with the detection system will not start if sweat sensors in the steering wheel detect high levels of alcohol in the driver's bloodstream.
The system could also kick in if the sensors detect abnormal steering, or if a special camera shows that the driver's pupils are not in focus. The car is then slowed to a halt.
Concerns over drunken driving have surged in Japan following a series of alcohol-related accidents last year. In August, a drunken driver collided with another vehicle carrying a family of five, plunging them off a bridge and killing three children.
The incident prompted stepped-up roadside spot checks by police, who also plan to stiffen penalties for drunken driving.