Communication campaigns are used as a rather efficient strategy to approach the wide audience in terms of promoting road safety and improving driving behavior. Incorporation of the evaluation in the campaign design is considered of high importance, since it provides information about the effectiveness of the campaign. Literature review on road safety campaigns, conducted in the last decade, highlights the importance, as well as the limited application of a well structured theoretical background when designing and implementing a road safety campaign, that could enable predicting possible behavioral changes of the road users owing to the campaign, and facilitate the assessment of its effectiveness. The scope of this study is to examine the predictability of alternative research designs as regards driving behavior, when evaluating the effectiveness of road safety campaigns; moreover, to assess the impact of the various parameters and predict behavioral changes. The conclusions drawn rely on the results of the assessment of the impacts of two local campaigns, one on drink and drive and the other on seat belt usage, both implemented on a university campus, with its 1587 students (drivers and passengers) forming the target group. Both campaigns were designed taking as a premise for design and assessment the Theory of Planned Behavior, and an attempt was made of developing alternative models for correlating behavior and intentions with behavioral beliefs, control beliefs, normative beliefs, and descriptive norms. Increase of the predictability of the models was noticed as more constructs were being added; especially, when past behavior was added in the models predicting intention, and intention in the models predicting behavior. This demonstrates the high correlation between these two constructs. The theoretical and applied implications of the models are discussed. (c) 2013 Elsevier Ltd. All rights reserved.