Driving under the influence is against the law, plain and simple.

So if you are intoxicated, or even think you may still be over the legal limit; the best course of action is always to wait for the alcohol to leave your bloodstream before you drive.

But if you are pulled over by the police, who feel you may be driving after drinking, they will often ask you to carry out a number of “tests” to determine whether to make an arrest.

Although a blood or breath sample is normally required before charges can be brought, the sobriety test is still one of the most commonly used methods in tackling drunk drivers.

So if you are stopped on suspicion of a DUI or DWI, here is what might be expected of you.

1. Horizontal and Vertical Gaze (Nystagmus Test)

Nystagmus is an involuntary twitching of the eye, which typically occurs when a person uses their peripheral vision by looking sharply to the side (45 degrees) with the head held in the forward position. When alcohol has been consumed, this twitching occurs at a lesser angle and the driver has difficulty following the object with his or her eyes.

Also known as a Nystagmus test, an officer will hold an object about twelve inches in front of a driver’s face, and move the object from side to side watching the driver’s eyes. If any jerking or trembling of the eyeball is seen the officer will, more often than not, assume you are intoxicated.

2. Walk and Turn

An officer will request that you walk a heel to toe line, turn and then take nine steps back. This is a balance test and should you sway or lose coordination at the turn, then you could be suspected of being intoxicated. Obviously losing your balance does not automatically mean you have been drinking – it’s just an indicator.

3. One Leg Stand

Similar to the walk-and-turn test, the one-leg stand test is designed to divide attention. In other words it requires you to divide your attention between the mental task of following oral instructions and the physical task of balancing on one foot.

In this test, you must stand with one foot approximately six inches off the ground with your toe pointed. While maintaining perfect balance, you’ll be asked have to count for up to 30 seconds and keep your arms firmly at your side. All the time the police officer will observe you for impairment or signs of intoxication.

4. Finger to Nose

This test involves standing up straight with your feet together, closing your eyes, extending your arms and touching your finger to your nose. The pressure is enough to reduce the coolest customer to a nervous wreck as you will “fail” this test if you begin too early, have trouble maintaining your balance, miss your nose or show any sign of muscle tremors.

5. The Rhomberg Balance Test

The officer will instruct you to stand to attention, close your eyes, tilt your head back and estimate how long thirty seconds lasts. They will be looking for any muscle spasms or tremors and to see whether alcohol might have slowed down your perception of time.

While making sure you don’t lose your balance, suffer a cramp attack or bring on a spasm, whatever you do, don’t forget to count to 30.

6. The Hand-pat test

Another test of concentration while multi-tasking, you are asked to extend a hand in front of you, palm upwards. The other hand is then placed on top of the first hand, palm downwards. You’ll then be requested to ‘pat’ the lower hand with the upper hand while rotating the whole thing, so that first the lower hand is patted with the palm of the upper hand and then with the back of the upper hand, so on, and so on.

Sound confusing? Well that’s because it is. So any kid who was terrible playing pat-a-cake at school might have reason to be concerned!