The new police roadside drug test in the UK will use a saliva drug testing kits which can detect drugs in saliva, for up to several hours after last use.
The aim of the new test is to detect whether there has been very recent consumption of drugs by the driver, and whether they are under the influence of drugs while driving.
The drugs that can be detected with this initial test that the police will be using are Cannabis, Cocaine and Crack Cocaine.
Opiates including Heroin and Morphine , Amphetamine , Benzodiazepines, Methadone and Methamphetamines also impair driving ability, and in years to come these drugs may also be tested for at the roadside on the same test.
Saliva drug testing gives a shorter detection window generally than urine drug testing with most drugs. Cannabis for example is only detectable in saliva for up to a maximum of 12 hours after last use.
This means that saliva drug testing is a very good indication of whether the driver is under the influence of drugs at the time of the test.