Drug drivers are to be targeted by the government's first national TV advertising campaign to tackle users who get behind the wheel.
One in 10 young male drivers admit to driving after taking illegal substances, according to research by road safety body THINK!, and one in five drivers killed in road accidents may have an impairing drug in their system.
Police spot drug drivers by the involuntary effects that substances have on the user's body, which the new £2.3 million campaign highlights in its slogan: "Your eyes will give you away".
Punishment for drug driving is equally as tough as penalties given to drink drivers, with a minimum of a 12-month driving ban and a maximum fine of £5000.
The government is also keen to highlight that prescribed drugs can also lead to a drug-driving penalty, and is urging anyone using them to consult their doctor.
If police think that a driver is impaired by drugs they will perform a Field Impairment Assessment (FIA). The FIA is made up of five tests:
1) The Pupil Measure Test. Examination of the driver's pupil size, condition and reaction to light.
2) The Romberg Test. This test assesses the subject's balance and judgement of time. The subject is asked to tilt their head back slightly, close their eyes and estimate the passage of 30 seconds.
3) The Walk and Turn Test. The subject must walk heel to toe along a straight line, counting their steps out loud and looking at their feet while doing so.
4) The One-leg Stand Test. The subject must stand on one leg while counting out loud.
5) The Finger-to-nose Test. With the head tilted slightly backwards and eyes closed, the subject must touch the tip of their nose with the tip of their finger with the hand indicated by the officer.