Most people know the dangers of driving under the influence of alcohol these days and, thankfully, are responsible enough to avoid this. However, although you don’t drink and drive when you’re on a night out, if you’ve had an especially heavy evening of socialising, then it’s not out of the question that you might still be unfit to drive the next day. A lot depends on your body mass and how much you’ve had to eat along with the level of alcohol that you’ve taken on board. One way that you can be certain is to use your own breathalyzer to check - you can even get a tiny little breathalyzer keychain these days - and they are very accurate.