From the National Institute on Drug Abuse, NIDA InfoFacts: Drugged Driving, What is Drugged Driving?

Some States (Arizona, Delaware, Georgia, Indiana, Illinois, Iowa, Michigan, Minnesota, Nevada, North Carolina, Ohio, Pennsylvania, Rhode Island, South Dakota, Utah, Virginia, and Wisconsin) have passed “per se” laws, in which it is illegal to operate a motor vehicle if there is any detectable level of a prohibited drug, or its metabolites, in the driver’s blood. Other State laws define “drugged driving” as driving when a drug “renders the driver incapable of driving safely” or “causes the driver to be impaired.”

In addition, 44 States and the District of Columbia have implemented Drug Evaluation and Classification Programs, designed to train police officers as Drug Recognition Experts. Officers learn to detect characteristics in a person’s behavior and appearance that may be associated with drug intoxication. If the officer suspects drug intoxication, a blood or urine sample is submitted to a laboratory for confirmation.

Check out the full article, it's pretty good, and current through December, 2010, although it would have been nice if it included a list of the prohibited drugs in the 17 "per se states." http://www.drugabuse.gov/Infofacts/driving.html

I for one am happy not to live in a "per se state." Meaning, I believe, that it remains the state's burden to prove impairment. Hence the officer training to record (among other things) behavioral evidence of impairment/intoxication.

Mike

PS to Anita: please note that Delaware appears, in fact, to be a per se state. If this is correct, I don't know where your attorney could possibly have been coming from.

PPS For those of you who do live in "per se states," it would be good to know to how many of your pain management physicians (or pharmacists) advised you of that fact, before handing out presumably "prohibited" drugs.