Communication campaigns are commonly used in the traffic and road safety sector to raise public awareness of the importance of avoiding risky road user attitudes and behaviors. Surprisingly few of these communication campaigns evaluate their effectiveness in a formal and comprehensive manner. The core aim of the present systematic review is to identify the type of studies that evaluate the effectiveness of campaigns in this sector, in order to identify and contrast their main findings. This systematic review followed the PRISMA methodology, by means of which the relevant articles based on the search term were identified. A total of 613 indexed articles were filtered, and a final set of 27 articles directly addressing the issue was analyzed. Search strategies were developed and conducted in WOS, Scopus, NCBI, Google Scholar and APA databases. The selected articles point out that, although advertisements alone have a certain positive effect, their effectiveness is substantially increased if they are accompanied by other preventive measures such as legislation or road safety education. In any case, more evaluations of traffic campaigns are needed to identify which techniques are effective and which are not, and which should therefore be replaced by new methods of behavior modification in future communication campaigns.