Patent ID: 8201437

Claim:
An alcohol detection system for a vehicle comprising: an alcohol detection section that detects alcohol concentration in breath air of a user seating in a driver's seat in a vehicle, the alcohol detection section including a measurement chamber for receiving the breath air of the user to be measured and a fan for exhausting residual gas in the measurement chamber; a measurement preparation operation section that performs at least driving operation of the fan, as an alcohol measurement preparation operation, which changes the alcohol detection section from an initial state to a predetermined stable operation state; a travel control section that permits normal travel of the vehicle when alcohol concentration measured under the predetermined stable operation state is below a predetermined threshold level, and prohibits travel of the vehicle over a predetermined travel speed when the alcohol concentration is over the threshold level; a pre-driving output signal detection section that detects a predetermined pre-driving output signal outputted necessarily before an ignition switch is manipulated by the user entering the vehicle from an outside of the vehicle; and a measurement preparation operation start instruction section that instructs the measurement preparation operation section to start the measurement preparation operation when the pre-driving output signal is detected.