In this study, a new measure was used to measure alcohol as a contributing factor in vehicular accidents. A 7-hour time period (10:00 p.m. - 5:00 a.m.) was segregated for analysis and used as a measure of alcohol and driving. Analysis on all criteria was performed comparing the average of the 3 years directly preceding the initiation of the Traffic Options Program for Driving While Intoxicated (STOP-DWI) with the accidents occurring in the first year of the program. Initial findings indicate that New York State experienced a decrease in severity of motor vehicle accidents in 1982 compared to the previous 3-year average. In addition to hypothesizing that STOP-DWI contributed to this decrease, other hypotheses tested focused on severe weather, the economy, restraint usage, vehicle mix, reduced speed, and emergency medical care. These alternative hypotheses, such as weather and economy, do provide some explanation of a portion of the decline, but fail to account for the ability and the entire scope of the phenomenon. The fatal accident decline commenced coincidentally with the enactment of the STOP-DWI program, and historically, all other steep declines have been associated with specific 'social events,' such as the Depression, the war years, and the years of the oil embargo and gas shortages. Each month since the program began, the number of deaths was lower than the same month's total for the previous year. The hours of presumed greatest proportion of drinking drivers being on the road showed the greatest decrease in fatal accidents. Graphic data are provided.