Is this the key to stopping drunk drivers?

There are already a number of high-tech devices either on the market or in development focused on helping drivers know their alcoholic limits.

The most high-profile is the DADSS, a system being developed by the US Department of Transportation's National Highway Traffic Safety Administration that could soon become standard in-cabin equipment on new cars sold in North America.

However, what sets Honda's portable alcohol detection device apart from the others is that it is mobile -- it can be used anywhere and at any time as a breathalyzer. This mobility means, according to its makers, that a user doesn't have to get into his or her car to perform a breath test. This minimizes any temptation to drive.

Likewise, the fact that it's integrated into the car key means that three seconds after providing a breath sample, if too much alcohol is detected, the key will no longer open or start the car.

In order to build a breathalyzer compact enough to fit into a key not much larger and thicker than a credit card, Hitachi had to develop a sensor that was tiny (just 5mm in area) yet good enough to detect as little as 0.015mg/l of ethanol concentration in a person's breath. It achieves its readings by also measuring exhaled hydrogen and metabolized acetaldehyde and by using an algorithm to make a calculation based on the concentration of the three substances.

Though just a prototype at the moment, Honda and Hitachi want to commercialize the device and the technology behind it quickly. And to do so it will have to go through rigorous testing in terms of its accuracy. It is currently calibrated in accordance with Japan's drink driving laws but the intention is to tune the smart key for different markets and laws.