An estimated nine million Americans a year drive while under the influence of illegal drugs, but efforts to identify, arrest and treat them have been hampered by the weakness of state laws and, until recently, a lack of quick and reliable drug tests, a new report says...

Washington, DC, Nov. 14—Unlike alcohol, state laws on driving under the influence of drugs (DUID) in the U.S. vary so much that there are significant differences in how drugged driving is defined and how a charge of drugged driving can be proven or defended...

WASHINGTON -- State laws haven't kept up with advances in technology making it easier for police to determine whether a driver is under the influence of drugs, according to a study released Thursday. People who drive under the influence are rarely detected, prosecuted or referred to treatment programs...