As we have said many times before, it isn't always easy to tell if you have had too much to drink and hence should not drive. So, if there were a smartphone app that could help you decide, would you use it? Would you trust it? In fact, should you trust it?

Three men say they have developed such an app. Called the BreathalEyes, the app works by using a smartphone's camera to take a series of photographs of a user's face as he or she moves his eyes side to side horizontally. The app then analyzes the photographs to determine whether the user's eyes are involuntarily jerking back and forth -- that's a reaction to intoxication and is the same thing police are looking for during a field sobriety test when they ask you to follow a pen with your eyes.

The founders claim the app is accurate with a range of 0.02 and 0.017. That's pretty good, but when the difference between getting off scot-free and facing thousands of dollars in fines, possible jail time and maybe even restrictions on your driver's license, every percentage point counts. It is also unlikely any court would entertain your argument that a smartphone app said you were okay to drive.

The founders say BreathalEyes will never tell you whether you should or should not drive because that decision rests with the user. Ultimately, this app sounds like it might be interesting and may have some usefulness, but in the end, your judgment may be a better guide. If you are worried you are too drunk to drive, it is probably better to just take a cab.

Source: Insurance Journal, "Drunk Driver Test? There's an App for That," Jan. 4, 2012