In  1988 the Harvard School of Public Health launched one of the best documented examples of a successful media effort to change public health behaviour: the designated driver campaign. The campaign, that was strongly supported by the leading broadcast networks, Hollywood studios, government agencies, non-profit groups and corporations, demonstrated how a new social concept, the designated driver, could be rapidly diffused through American society via mass communication.
The campaign broke new ground when television writers agreed to insert drunken-driving-prevention messages, including references to designated drivers, into the scripts of top-rated television programs. Networks also aired frequent public-service announcements during prime time that encouraged the use of designated drivers. Studies showed that this sustained media blitz contributed to a fundamental shift in social norms, in this case related to driving after drinking.