TOKYO – Toyota Motor Corp. is developing a fail-safe system for cars that detects drunken drivers and automatically shuts the vehicle down if sensors pick up signs of excessive alcohol consumption. Toyota hopes to fit cars with the system by the end of 2009. Cars fitted with the detection system will not start if sweat sensors in the driving wheel detect high levels of alcohol in the driver’s bloodstream, according to a report carried by the mass-circulation daily, Asahi Shimbun. 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. Nissan Motor Co. has already experimented with breathalyzer-like devices that could detect if a driver was drunk. Similar technologies, such as alcohol ignition interlocks, are in use in the U.S. and elsewhere.