There is little evidence that stand-alone mass media communication is effective in changing behaviour or improving road safety. Publicity campaigns are rarely evaluated for changed behaviour and even less often for crash reduction. Evaluations often only measure awareness of the campaign, slogan and/or message (see also the questions How effective is the Bob campaign? and How effective is the MONO campaign?). Effectiveness of public communication is also difficult to determine because it is often combined with other measures (such as intensified traffic enforcement). Subsequently, it is hard to determine which measure was effective.
Reviews of international research do conclude that campaigns have a positive effect on road safety [2] [3] [4] [5]. However, because most campaigns are accompanied by other activities (such as intensified enforcement), it cannot be determined what the specific contribution of the campaigns was. There are also some studies that do show an effect on behavioural intention; after seeing a publicity campaign, people say that they will behave differently. But research shows that an average to high intention to change behaviour leads to a small or average actual behavioural change at most [6]; the so-called Intention-Behaviour Gap [7]. Because of this difference between intention and behaviour, based on behavioural intention alone, no firm conclusions can be drawn about the effectiveness of public communication in preventing road crashes.
Research does show that campaigns can help increase support for and knowledge of laws and regulations [8]. However, what effect this has on road safety is less clear. Evaluations of the theory section of driving tests, for instance, show that knowledge of laws and regulations probably has a limited effect on road safety (see SWOV fact sheet Driver training and driving tests). It is known, however, that greater support ensures better compliance with traffic rules [9] [10] [11] [12], which has a positive effect on road safety.
