DRUG driving is becoming a consistent problem among Britain's drivers and has brought calls from road safety organisation GEM Motoring Assist for more action.
GEM is worried about inconsistencies in sentencing of offenders and by the large number of offences being committed by reoffenders.
In response to a report by the Parliamentary Advisory Council for Transport Safety, the organisation is calling for an end to the significant variation in enforcement levels between police forces as well as greater consistency in sentencing offenders.
It is also supporting a call for rehabilitation courses - along the lines of those which have been available for drink drive offences - to reduce reoffending.
GEM chief excecutive Neil Worth said: "The new roadside drug testing kits introduced in 2015 make it simple for police officers to detect the presence of drugs in a driver's system. Furthermore, drug driving limits are set at very low levels, and there are also limits for some prescription medicines.
"However, each police force chooses how much of its budget to spend on drug screening kits, and it is for local police to decide how to best use the number of kits they have. We are concerned that levels of enforcement vary so much from force to force.
"Let's be clear: driving under the influence of drugs is extremely dangerous and entirely inappropriate. This is why we fully support the recommendations of the PACTS report and call for greater consistency in sentencing.
"It is vital to send a strong safety message to those who consider it acceptable to drive after taking drugs."