Drug-driving arrests increase 600% after law change

Roadside tests and a zero tolerance approach have seen the number of arrests for drug-driving increase by more than 600% in some police force areas - but how are the roadside tests actually carried out?

BBC Breakfast's Jayne McCubbin joins police on patrol to catch drug-drivers, asks one motorist whether he believes he was in full control of his vehicle, and is then kitted up in a special sensory suit which recreates the impairment of being on drugs while she carries out some motoring manoeuvres..