STATISTICS FROM A VARIETY OF STUDIES ON THE NATURE OF DRINKING AND DRIVING INCIDENTS IN THE TOTAL DRIVING POPULATION ARE PRESENTED AND DISCUSSED. OTHER STATISTICS SHOW THE RELATIONSHIP OF ALCOHOL CONSUMPTION TO IMPAIRMENT, THE TENDENCY OF DRINKING DRIVERS TO BE FOUND DURING THE EARLY MORNING HOURS AND ON SPARSELY TRAVELLED ROADS, AND THE CHARACTERISTICS AND DRIVING PATTERNS OF IMPAIRED DRIVERS. STUDIES OFFERING VARIOUS ESTIMATES OF DWI OFFENSE PROBABILITIES ARE CITED. THE DEARTH OF EVIDENCE THAT DWI ENFORCEMENTS EFFORTS DETER DRINKING DRIVERS IS NOTED, TOGETHER WITH THE OBSERVATION THAT MANY DRINKING DRIVERS CONTINUE TO DRINK AND DRIVE EVEN AFTER APPREHENSION AND CONVICTION. INFORMATION PERTINENT TO THE PLANNING OF PATROL ACTIVITIES INTENDED TO MINIMIZE DWI ACCIDENTS-WHERE AND WHEN TO PATROL-IS PRESENTED. ANSWER-KEYED QUESTIONS ARE INCLUDED AS STUDY AIDS. FOR OTHER MARYLAND TRAINING DOCUMENTS ON DWI PROCEDURES, SEE NCJ-52080 AND 52082-52084. (LKM)