Behavioral impact of a corporate driving policy : undesirable side-effects reflect countercontrol.

Pizza deliverers at two stores received turn-signal policy statements with two paychecks in an AB1B2 multiple baseline design. At Store A turn-signal use rose from a baseline mean of 70% to 78% after the first policy statement and to 84% after the second policy statement. At Store B turn-signal use rose from a baseline mean of 46% to 51% after the first policy statement and to 59% after the second policy statement. Concurrent observations of safety-belt use showed decreases from 78% to 65% at Store A and 74% to 59% at Store B after the first policy statement. (A)