The Federal Motor Carrier Safety Administration (FMCSA) recently released the results of its 2001 Drug and Alcohol Testing Survey, which measures the percentage of CDL holders who tested positive for controlled substances.

The estimated positive usage rate for drugs, based on random testing in 2001, was 1.5%. For 2000, this rate was estimated to be 2.0%. Based on the levels of precision achieved for these two survey years, the change from 2000 to 2001 is not statistically significant, according to FMCSA.
Based on random alcohol testing in 2001, the estimated percentage of CDL drivers with a blood alcohol content of 0.02 or higher was 0.2%. The estimated violation rate for alcohol use (the percentage of drivers with a blood alcohol content of 0.04 or higher), based on random testing in 2001, was 0.1%. For 2000, the estimated violation rate was 0.2%. Again, the change in violation rate from 2000 to 2001 is not considered statistically significant.
Motor carriers with CDL holders are required to have drug and alcohol testing programs that randomly test 10% of their CDL drivers for alcohol and 50% of their CDL drivers for drugs each year. According to FMCSA, the positive usage rates presented by the study represent weighted statistical estimates generalizable to the entire population of CDL drivers in the national fleet. They were derived using standard statistical techniques applicable to stratified samples. FMCSA says the rates obtained from the study procedures do not represent true values, but rather unbiased estimates of the true rates, with associated sampling errors.
For the 2001 survey, forms were sent to 4,579 randomly selected motor carriers. A total of 3,748 of these forms were completed and returned to FMCSA, resulting in usable data from 1,336 carriers (comprising 332,526 CDL drivers) for random controlled substance testing, as well as usable data from 1,164 carriers (comprising 86,160 CDL drivers) for random alcohol testing.
Based on the 2001 survey results, FMCSA says the estimated percentage of all CDL drivers participating in random testing programs was 95%.