2007 National Roadside Survey of Alcohol and Drug Use by Drivers

2007 National Roadside Survey of Alcohol and Drug Use by Drivers: Drug ResultsOral Fluid and/or Blood Analyses CombinedSimilar patterns of results were obtained when we examined the drug prevalence for the 5,910nighttime drivers who provided oral fluid and/or blood samples. If a driver tested positive for oneor more of the drugs in either the oral fluid and/or in the blood analyses, he/she was categorizedas drug-positive (Table 110). This yielded an overall drug positive rate of 16.3 percent.When we examined individual drugs and their metabolites (Tables 137 and 138), we found thatthe most frequently encountered drug was marijuana, whether it was measured in oral fluid in thedaytime (4.5%), oral fluid at nighttime (7.7%), or the combination of oral fluid and/or blood atnighttime (8.7%). The next most frequently encountered individual drug (again by all measures)was cocaine, which was present in 1.5 percent of daytime oral fluid samples, 3.9 percent ofnighttime oral fluid samples, and 3.9 percent of nighttime combined oral fluid and/or bloodanalyses.During the daytime, the next most frequently encountered drug was alprazolam at 1.12 percent.Among nighttime drivers providing oral fluid samples, the most frequently encountered drugs,after marijuana and cocaine, were methamphetamine and oxycodone, each with a prevalence rateof 0.80percent. The data collected during the 2007 National Roadside Survey provides newinsight into the extent and patterns of drug use, and the combination of drug and alcohol use,among our Nation’s drivers. As noted earlier, the data collected can not determine whether thedrug-use patterns we observed affected driver performance, For example, although all the drugsexamined in this study can potentially impair driving skills, some of the drug-positive driverscould drive better with the therapeutic effects of medicinal drugs they are taking. What this studyhas provided is a careful estimate of the extent of alcohol-involved and drug-involved driving inthe contiguous 48 States.The next step in this process is to conduct a study that attempts to quantify the risk that druginvolveddriving may pose for crash involvement. One way to establish that is to conduct a casecontrol study where data including objective measures of drug use are gathered from crashinvolveddrivers and non-crash-involved drivers matched to the time, location, and direction oftravel of the crash-involved drivers. Those two sets of data can then be compared to estimate therisk posed by various drugs.114