A simple swab test, being used across the county from today, will help police to catch drivers who have been taking cannabis.
Normally, if officers suspect somebody of being under the influence, they have to use a ‘field impairment assessment’.
This involves looking at the driver’s eyes, and testing their balance and co-ordination.
If they fail any of the tests then police have to get a doctor to carry out a blood test, which provides them with evidence that they can use in court.
Getting a doctor can take several hours and in the meantime the driver - who might turn out to be innocent - has to be kept under arrest, taking up their time as well as the police’s.
A new method, which Sussex Police will be trying out over the festive season, gets around the need to involve a doctor.
A mouth swab test, which can be carried out at a police station in a matter of minutes, checks the driver’s saliva for traces of tetrahydrocannabinol (THC) - the main psychoactive ingredient of cannabis.
CI Natalie Moloney said they would still need a blood sample to give them the evidence to go to court, but this can be taken by police staff.
She added that the law does not yet define what level of cannabis a person has to have in their system to be guilty of driving while unfit through drugs.
This contrasts with the law on drink driving, which has set legal limits for alcohol in breath, blood and urine.
PS Stewart Goodwin of Sussex Police roads policing unit, said: “We would present a case to the court, to say that the driver was impaired.
“A forensic scientist will analyse the result to give their opinion on whether the driving would have been impaired.
“It’s up to the magistrates to decide.”
Sussex Police and Crime Commissioner Katy Bourne was at Haywards Heath police station for a demonstration of the machine on Friday.
She said: “During my election campaign I pledged to lobby Government to make driving under the influence of drugs as equally unacceptable as drink driving.
“I welcome this move by Sussex Police to use Home Office-approved drug screening devices in custody suites over the Christmas period.
“I believe screening of this nature is an effective deterrent and I will be supporting investment in technology that enables officers to make these checks.
“Residents have told me that road safety is one of their main concerns and I am determined to tackle this problem during my term in office.
“I would like to see communities becoming more involved in playing their part in making Sussex safer by supporting initiatives like Operation Crackdown to tackle antisocial driving. Safer roads and communities can only be created by working together and sharing the roads responsibly.”
The machines are on loan from German-owned manufacturer Dräger, paid for with Sussex Safer Roads Partnership funds.
Although the same machine can be used to check for a whole range of drugs, the Home Office has so far only approved it for use as a cannabis tester.
CI Moloney said that, if the Home Office testers approve it for other drugs, they may buy some of the machines for long-term use.