Hitachi and Honda Motor have developed a prototype of a portable alcohol detector that is tamper-resistant as it can distinguish human breath from alternative gases. This device is capable of detecting the saturated water vapor from human breath and accurately measure alcohol level within 3 seconds once a driver exhales breath onto it.

Hitachi and Honda also developed a system that can show the alcohol level measured by the detector on the vehicle's display panel. It can become an ignition interlock to stop a vehicle from starting its engine when it detects a drunk driver.

The prototype developed by Hitachi and Honda has advantages over the other ignition interlocks. These other systems require drivers to perform the test from the driver's seat once they are already inside the vehicle. With the Hitachi/Honda device, drivers can measure their alcohol level from anywhere and, importantly, before entering their vehicle. In addition, the device can confirm that the applied gas is human exhaled breath and can detect the level of alcohol at the same time.

The device is highly portable and battery powered. It is capable of measuring as little as 0.015 mg/L (an ethanol concentration) compared to 0.15 mg/L of the alcohol which constitutes being "under the influence of alcohol" and a charge of drunk driving in Japan.

Hitachi and Honda are aiming to commercialize this technology sometime in the near future, since more validation tests should be performed.