Essex Police can stop you and conduct a roadside screening test or a field impairment test, both of which may result in your arrest if:

• They think you have taken drugs.
• You’ve committed a traffic offence.
• You’ve been involved in a road traffic collision.

Even if you pass the roadside check, you may still be arrested if the police suspect that your driving is impaired by drugs, and you can be taken to a police station for further tests.

An arrest can still be made if there is a negative screening test at the scene, if the police believe a driver is impaired through drink or drugs (both prescription and illicit). Upon arrest, a blood sample is taken for forensic analysis to determine the exact level of drugs in the system for evidential purposes.

The drugs that Essex Police can test for are:

Amphetamine
Benzoylecgonine
Clonazepam
Cocaine
Delta-9-Tetrahydrocannabinol (THC from cannabis)
Diazepam
Flunitrazepam
Ketamine
Lorazepam
Lysergic Acid Diethylamide (LSD)
Methadone
Methylamphetamine
Methylenedioxymethamphetamine
6-Monoacetylmorphine
Morphine
Oxazepam
Temazepam

Penalties
If you're found to be driving while impaired by drugs, you can receive:

• a criminal record
• a maximum penalty of six months in prison
• an unlimited fine
• an automatic driving ban of at least one year (three years if you have been convicted twice in 10 years)

Other problems you may face include:

• an endorsement on your driving licence for 11 years
• an increased insurance premium
• if you drive for work, your employer will see your conviction on your licence.
• trouble travelling to countries like the USA.

If a driver kills someone while under the influence of drugs, they can be charged with causing death by dangerous driving while under the influence of drink or drugs, which carries a maximum sentence of life imprisonment.