Several European countries have either already implemented oral fluid analysis for the detection of drugs in drivers or are contemplating its utility. In the USA, researchers involved in roadside surveys are increasingly including oral fluid collection and analysis in order to establish prevalence rates for drugs in drivers and decide whether oral fluid testing is reliable in this context.

Oral fluid provides several advantages over blood, such as ease and speed of sample collection, particularly in terms of proximity to a traffic incident. Recently, several studies have been carried out with the specific aim of determining whether oral fluid, when collected simultaneously with blood provides similar information about recent drug intake.

Drivers are stopped and are asked to submit voluntarily to the collection of an oral fluid and blood sample. In 2007 and 2013 over 7000 oral fluid and 3000 blood samples were collected nationally in the USA and analyzed for a wide range of drugs. In other projects, roadside instruments using oral fluid for analysis were also evaluated in conjunction with police officer observations and blood tests.

Oral fluid provided similar information to blood regarding the recent intake of drugs. The overall results of several surveys will be presented, along with a discussion of the issues associated with practical aspects of saliva testing such as collection, analysis and interpretation. The outcome from several state projects, which incorporated the use of rapid oral fluid, tests using roadside instruments also provided supportive data and results will be presented. Rapid test instruments have a limited drug test panel and lack sensitivity for the detection of benzodiazepines in particular, which tend to be present in low concentrations in oral fluid compared to blood. The advantages and drawbacks of using oral fluid as a drug test specimen will be highlighted.

Oral fluid is being increasingly studied for use in the area of driving under the influence of drugs. It has been shown to provide similar information to blood. Roadside instruments have been evaluated and some have been shown to be reliable, however improvements in the detection of benzodiazepines as well as extended drug test panels are necessary.