A new method of detecting whether a driver is under the influence of drugs is to be tested at Lausanne University, using sweat samples from a person’s forehead.
Germany, France and Finland are already using similar tests.
The detector, called "Sweat Scan", will be examined by the toxicology laboratory at the University Institute of Forensic Medicine in Lausanne (IUML). The tests are being carried out in conjunction with the Judicial Identity Service of the Fribourg police, during 2003.
The aim is to implement the test in Fribourg in 2004, to coincide with the introduction of new road legislation, which will extend the drink-driving laws to cover abuse of narcotics and medicinal drugs.
Once put into effect, the test would enable police to immediately detect the presence of drugs in a driver's system by simply taking a sample of sweat from their forehead.
All four of the main drug groups - opiates, amphetamines, cannabis and cocaine - can be detected by the test.
Fribourg police expect "Sweat Scan" to detect more cases of drug use than current blood or urine tests. Because the sweat sample can be taken immediately on the roadside, the new scan would also be far less time-consuming to carry out.
The "Sweat Scan" may have its limitations, however. It will be able to detect whether or not someone has taken drugs, but not how much.
Marc Ausburger, director of the IUML, said police would still need to use traditional testing methods to back up the "Sweat Scan".
"The police will use the [new] test on the driver. The IUML will then intervene with blood and urine tests, to confirm the findings of the 'Sweat Scan'," he told swissinfo.
The "Sweat Scan" is also unable to determine the exact drug taken by the driver, Ausburger added. It can, for example, detect opiates, but cannot determine whether the drug was codeine, morphine or heroin.
The test also needs to be refined so it can determine how long ago a drug was taken. "We don't yet know how long it takes for the test to detect the drug after it has been taken," Ausburger explained. "More precise work on the test should determine this."
If the test comes into use, laws governing drug use for drivers will have to be updated accordingly. Parliament has yet to decide whether there should be a legal limit on the amount of drugs taken, and if so, for which drugs, narcotics or medicines.
Scientists at the institute will spend next year testing the "Sweat Scan", partly to check for margins for error in the detector's results. They will also conduct more research into how the human body reacts to other substances, such as medicines.
They already have encouraging signs from tests carried out in England. The transport ministry there found that 18 per cent of UK drivers tested positive for drugs when their sweat was analysed. Police detected less than two per cent using the current methods of blood and urine samples.
swissinfo, Joanne Shields
The test can detect cannabis, amphetamines, opiates and cocaine in the driver's sweat
Fribourg plans to introduce the test in 2004.
A new road law on drug and medicine abuse comes into force in 2004.