Police today began a new crackdown on drug-driving.

They are implementing a new law, which came into force today, making it illegal to drive with set limits for both illegal and certain legal drugs for the first time.

The new legislation makes it easier for police forces to target drug-drivers because the law now sets limits for certain drugs- meaning police can test drivers for drugs in a similar way to how they currently test for alcohol.

And officers on the county’s roads have been equipped with new test kits to help them trap erring drivers.

Limits are set at very low levels for eight illegal drugs including cannabis and cocaine while some legally prescribed drugs including diazepam and methadone are also included as certain strong medication can affect people’s ability to drive.

Class A cocaine and class B cannabis have been deliberately chosen as they have been found to be the most prolific drugs used by those drug-driving and can have significant levels of impairment when it comes to people’s ability to drive.

The new testing kit means police can test for the presence of cannabis and cocaine at the roadside. In a first for the Force the new kit means anyone suspected of driving while under the influence of drugs can be tested with a saliva swab and then arrested if the test proves positive. Previously, the offence of driving whilst unfit through drugs would be used to prosecute drivers, but the new laws are in addition to this existing offence.

Insp Joanne Field, who leads West Yorkshire Police’s Roads Policing Unit, welcomed the new legislation. She said: ‘‘The change in law with set limits for both illegal and some powerful legal drugs makes the process of tackling those who put lives at risk by drug-driving simpler by enabling us to test for the two most common illegal drugs at the roadside.

‘‘The influence that drugs, both illegal and medication prescribed by a doctor, can significantly impair someone’s ability to drive and put your life as well as those of other road users in significant danger- just like drink-driving.

‘‘Cannabis and cocaine are the most common illegal drugs used by people who drug-drive and this new legislation increases our ability to identify and arrest people who drive with illegal drugs in their system.

‘‘Because the new law also sets limits for types of legal drugs it’s vital that anyone taking prescribed medication reads the instructions carefully and sticks to the prescribed dosage. If you have any concerns regarding the impact any medication may have on your ability to drive, please speak to your doctor before you get behind the wheel.

‘‘A drug-driving conviction will result in a criminal record, a minimum 12 month driving ban, a fine of up to £5,000 and up to 6 months in prison or both. It’s not worth the risk.’’