A survey of the San Diego-Tijuana cross-border binging. Methods and analysis.

On a typical weekend night between 12:00 a.m. and 4:00 a.m., about 4 thousand Americans 25 or younger cross back into the United States from a night in Tijuana, Mexico, clubs. More than 40% of the drinkers return the next morning with an illegal blood-alcohol concentration (.08 or higher). To study this phenomenon and to provide data with which to evaluate the community effort in San Diego County, a border research effort involving two separate surveys of individuals entering and leaving Mexico was established in June 1997. This article briefly reviews past roadside survey studies and reports on the survey methods developed to conduct these surveys and the procedure required to analyze the data collected.