Motorists who put other road users in danger can now be caught and prosecuted more easily after a new law came into force on Monday.

The law has set limits for eight commonly-used illegal drugs, including cannabis and cocaine, and eight prescribed drugs including painkillers and sleeping or anxiety pills such as morphine and diazepam.

Insp Phil Bloor from the Beds, Cambs and Herts Road Policing Unit welcomed the new law and explained how it will make the job of catching drug drivers much easier.

“Before if you stopped someone and suspected they were under the influence of drugs you had to prove their driving was impaired by their drug use,” he said.

“Now that a limit has been introduced this is no longer the case. If a person is over the limit they can be prosecuted which makes it easier to enforce the law and make the roads safer.”

All of the county’s traffic units now carry a roadside testing kit which can quickly indicate the level of cannabis and cocaine which may be in a driver’s system.

For other drugs a Field Impairment Test, which requires motorists to perform a series of physical tests like walking in a straight line, will be used to indicate whether they are safe to be behind the wheel.

Failure of any of the tests can result in arrest and further assessment at a police station.

The limits for prescription drugs are higher to allow motorists to drive legally as long as they are not impaired and take their medication as directed.

But they can be prosecuted if they take more than the prescribed amount or do not follow medical advice.

Insp Bloor said anyone with concerns about their ability to drive on prescription drugs should consult their doctor or pharmacist.

A drug driving conviction carries a minimum 12-month driving ban and a fine of up to £5,000.