Answer: Use Designated Drivers

Starting in 1988, the Harvard Medical School, through the Harvard Alcohol Project, conspired with both Hollywood and the major television networks like ABC, NBC, and CBS to insert a new notion into the American consciousness: designated driving.

At the time, alcohol-related car crashes were the leading killer of Americans aged 15-24 and the project sought to create and enforce the concept of designating one member of each party as the member who would abstain from alcohol for the evening and be capable of safely driving everyone else home. Over the ensuing years, script writers would insert the concept into movies, sitcoms, and television dramas and all the major networks aired frequent designated driver public service announcements. During the first four years of the project, over 160 prime time television programs incorporated the concept of a designated driver into the plot of the show.

The campaign proved enormously successful and by the end of the 1990s, the majority of adults surveyed had both been a designated driver and been brought home by one at some point.