This study investigates how timing of the introduction of unpleasant emotional tone in a traffic safety video impacts the intensity of the viewer’s emotional experience. Traffic safety advertising is a multi-million-dollar business in the United States. In many instances, 30–60 s ads are produced to raise awareness of the consequences of unsafe behaviors with the expectation that simply providing information will motivate safer behaviors. Producing videos intended to generate behavior change requires a complex understanding of what motivates behavior. Behavior change theory, neuroscience, and psychophysiology all provide guidance to improve the persuasive power of traffic safety videos. This study consisted of a 3 (message tone) × 3 (video) × 4 (order) repeated measures within subjects designed experiment. Participants (N = 75) were 20–30-year-old men who were shown nine traffic safety videos. Arousal intensity, attention, and negative emotion were tracked with the psychophysiological measures of skin conductance (measuring intensity of arousal), heart rate (measuring attention paid during the video), and corrugator muscle activation (measuring the negative emotional experience). Videos with three different aversive tones were used, low, high, and videos in which the tone switched from low to high aversive. Aversive tone is defined as stimuli that motivate a desire to escape or avoid something like death or pain. All videos were designed to prevent motor vehicle crashes. The results obtained from this study indicate that when attempting to persuade males aged 20–30 to practice safer driving behaviors, switched message tone appears to be the most effective message design in terms the intensity of emotional arousal and maintenance of attention.