Paid police overtime, supported by paid media, was used to mount a 5-month alcohol-impaired driving road check campaign, which checked drivers at a rate of about 21% of the area population per month. Public attitudes and awareness changed, drivers' blood alcohol content (BAC) levels dropped, alcohol-related crash surrogates fell below the projected levels, and a cost/ benefit ratio of about 1:​ 3.4 was realised in reduced crash costs for the insurer that funded the program. However, when police visibility and media levels fell off, crash proportions rose to non-enforcement levels, even though charge rates increased.