What is a roadside drug screening?

Roadside drug screening is the term used to describe the process of carrying out a drug test on a driver who has been asked to pull over to the side of the road and complete a test. It can also be known as Mobile Drug Testing (MDT) or Roadside Drug Testing (RDT).

Many drivers around the world are aware of the possibility that they could be stopped by law enforcement officials and asked to complete a random breath test. A portable breath tester can be used for random breath testing to detect an individual's alcohol use.

Less commonly known is the possibility of being stopped and asked to complete a drug test. Emerging technology allows drug testing to be carried out using a portable device. This means that it's possible for law enforcement officers to stop a driver and ask them to complete a drug test.

Why and how roadside drug screening may be conducted

Crash-based studies have identified drugs as being a contributing statistical factor in fatal car crashes. The overall goal of roadside drug screening is to increase safety on the road by reducing drug-related incidences.

A driver could be selected at random for a roadside drug test. A test could also be carried out in other situations; for example, at an accident site, or following the observation of dangerous driving.

In the past, law enforcement officials were limited to recognizing the signs that a driver may be impaired by drugs while driving. Indications could include speech impairment and behavioral signals. If a driver was suspected to be under the influence of illegal drugs, urine, or blood samples would need to be sent off to a laboratory.

Roadside drug tests use a saliva sample to test for the presence of illegal drugs. Current technology doesn't identify how much of a specific drug is in a person's system. The portable drug testing device simply detects that a specific substance is present.

In as little as a few minutes, a mobile drug testing device can detect the presence of specific illicit substances, without the need to send a sample to a laboratory or medical professional. The substances identified will depend on the technology that is used. Current technology may identify drugs such as THC, Methamphetamine, and MDMA, as well as prescription drugs.

The length of time that a particular substance can be detected via a roadside drug test will depend on a number of factors including the type of substance, dosage, and individual differences.