Local police agencies caused a stir three years ago by setting up roadblocks around the country designed to "voluntarily" swab motorists for drug use. The heavy handed tactics used at these locations sparked a lawsuit and the ire of at least one US senator, forcing the agencies to retreat -- for a time. The National Highway Traffic Safety Administration (NHTSA) announced last week that it is bringing back the controversial program.

"This study will estimate the prevalence of drugs in drivers arrested for impaired driving," NHTSA associate administrator Jeff Michael wrote. "The goal is to better understand the frequency of alcohol, prescription, over-the-counter, and illicit drugs, in impaired driving arrests."

Under the revised plan, one thousand motorists will again be asked to "voluntarily" consent to place a cotton swab in their mouth for five minutes so that it can be tested for the residue of fifty different drugs. The roadblocks will take place over six months at up to three sites around the country run by local police departments.

Drivers being arrested for driving under the influence (DUI) will be "informed" of the opportunity to participate in the study. Researchers will also ask the motorists a series of questions about their drug use.

"The results of the drug test and questionnaire will not be provided to anyone outside of the research team (including to the participant), and participation in the study will not be used to help or hurt the individual in any related legal proceedings," Michael explained.

In his 2013 lawsuit against the drug testing roadblocks, Ricardo Nieves complained that he was browbeaten by officers to take the test, which paid participants $10 for their time. Nieves settled the lawsuit after local officials and the survey company agreed to stop the testing.

The federal drug testing surveys conducted in 2007 and 2013 were funded both by NHTSA and the Insurance Institute for Highway Safety (IIHS). In the 2013 test, NHTSA identified 211 motorists who drove with traces of over-the-counter medications in their bloodstream. Another 597 had detectable amounts of marijuana, though the agency concedes that the test is unable to identify whether the metabolites that were found reflected a reduced ability to drive.

Public comments on the new survey proposal are due by November 6.