Traffic safety initiatives frequently involve passive measures such as building safer cars and roads. Traffic safety also involves driver behavior. A seatbelt is only useful if an occupant uses it. Traffic safety advertising has become a multi-million-dollar business in the United States. In many instances, 30 second ads are produced to raise awareness of the consequences of unsafe behaviors with the expectation that simply providing information will motivate safer behaviors. Video messaging intended to generate behavior change requires a more complex understanding of what motivates change. To be powerful, videos must capture attention and create a motivating emotional experience. Psychophysiology can provide guidance to improve the persuasive power of traffic safety videos. Psychophysiological measure can index cognitive and emotional processes underlying persuasion and provide insights beyond the traditional method of collecting self-reported impressions. This study consisted of a 3 (Message Tone) X 3 (Messages) X 4 (Order) repeated measures within subjects designed experiment. Participants (N=75) were 20–30-yearold men who were shown nine traffic safety video messages. Attention, emotion and arousal were quantitatively tracked through skin conductance (measuring arousal), heart rate (measuring attention paid during the video) and corrugator muscle activation (measuring the negative emotional experience). Three types of videos were used, one with pleasant (appetitive) content, one with negative (aversive) content and one in which the video started out pleasant, then switched to negative. The results obtained from this study indicate that when attempting to persuade males aged 20-30 to practice safer driving behaviors through exposure to video ads, switched content appears to be the most effective message design in terms of arousing motivation and maintaining levels of attention. On a practical level, the research suggests that for this demographic switching from low to high aversive content will hold viewer attention, and result in high levels of arousal.