As alcohol is a depressant drug, the activity of the central nervous system and most areas in your brain will get slow down. This will reduce the chance to drive safely, even though they look like un drunk and unaffected.
Alcohol slows down your brain functions, that leads to failure to respond to quick reactions, making decisions and react to the situations. Because it will reduce the ability to judge situations: how far you are from others car and how fast you are moving, you will not able to see the people or objects on the road. This gives you false confidence and it is important to have sense of balance when you are driving a car, but alcohol affects your sense of balance and makes you feel more relaxed and drowsy, this leads you to fall asleep on the wheel. You will fail to obey traffic rules, this may lead to take more risks.
Therefore, if you a plan to drive, don’t drink, more so if you are below legal age, because the risk will be associated with BAC (Blood Alcohol Concentration).
The small amount of the alcohol also can reduce the muscles coordination, hand and eye coordination and also make you very difficult in steering your car safely. This also leads to impaired ability to focus on your surroundings, and also in completing more than one task at a time. This will impact on increasing the chances of colliding with the objectives, another cars and even the pedestrians.
So there will be no safe driving once you drink alcohol whether it is small amount or huge. Better not to drive if you drink.