Drug-drivers face more rigorous tests after a kit for detecting cannabis was approved for use in police stations across the UK.
A positive saliva test with the new device means officers will no longer have to call a doctor before asking for a blood sample if they suspect a driver of being on drugs.
The testing kit is able to detect THC, the active ingredient in cannabis, while equipment capable of accurately identifying other substances is still under development.
Motorists can already be punished for driving while impaired by drugs, but the new testing equipment will make it easier for the police to prove a case
Offenders will face up to six months in jail and a fine of up to £5,000 as well as an automatic driving ban of at least 12 months.