Between 2000 and 2003, NHTSA supported demonstration programs in seven States to reduce impaired driving using well-publicized and highly visible enforcement.  The projects were conducted in Georgia, Louisiana, Pennsylvania, Tennessee, Texas, Indiana, and Michigan.  This report, "The Effectiveness of Seven Publicized Enforcement Demonstration Programs to Reduce Impaired Driving: Georgia, Louisiana, Pennsylvania, Indiana, Michigan, and Texas," Fell, J., Langston, E., Lacey, J. and Tippetts, S., DOT HS 810 940, PIRE, May 2008, describes the program evaluations conducted in each of these seven States.  Each State acted as a case study because the type and amount of publicity and enforcement differed substantially.  Download complete report here.