Arrests for drug-driving are on the increase after roadside swab tests for cannabis and cocaine were introduced last year.

In March 2015 legal driving limits were brought in for 17 illegal and prescription drugs, making it easier for police to prosecute motorists who are under the influence of substances. In the past, officers had to prove their driving had actually been impaired by drugs.

Figures from Cheshire Police show that arrests for drug-driving were up 800% with 530 arrests since the new legislation was brought in last year. This compares to just 70 drug-driving arrests the previous year.

Police forces across England and Wales have been given an additional £1 million so that they can buy drug screening equipment, pay for sample analysis and train officers in how to enforce the new law. Drivers can now be swabbed for cannabis and cocaine at the roadside while tests for other drugs are carried out at a police station.

Drivers are allowed to use prescription drugs, including morphine and methadone, but they must be within the recommended amounts.

Drug tests carried out over Christmas

According to the Department for Transport, 1,888 drug screening tests were carried out on motorists in England and Wales over the Christmas period. And of the tests which were carried out, almost half of them produced a positive result.

Andrew Jones, road safety minister, said: “Thanks to our tougher law, police are catching and convicting more dangerous drivers.”

Edmund King, president of the AA, said: “Drug-driving is often the hidden killer on UK roads. We need to make it as anti-social as drink-driving. The new law and greater enforcement will help achieve this.”

The new legislation is not in force in either Northern Ireland or Scotland but drivers can still be arrested if they are unfit to drive as a result of taking drugs.

Companies which employ drivers may want to screen their employees to make sure they are complying with the new drug-driving laws. AlphaBiolabs offers workplace drug testing to a wide range of businesses, including those in the transport industry, who want to make sure their staff are not abusing drugs.

There are a variety of tests which can be carried out, including urine tests, hair strand tests and analysis of saliva samples.