The impetus for this offence is to tackle the situation where a driver has taken drugs and drives but has avoided prosecution, because there has been insufficient evidence to prove impairment as prescribed by section 4 RTA 1988, “Driving whilst unfit”. There are currently 16 drugs listed in the related Drug Driving (Specified Limits) (England and Wales) Regulations 2014. The levels have been set and stated in the regulation. They are based on figures from a panel of experts that has considered such factors as “accidental exposure”. It is important to note that this offence is not a “zero tolerance” offence as asserted by some. It is also important to note that the Police can only test for three drugs at this stage: Cannabinoids, Benzodiazepines and Cocaine.