Previous research has shown that signal words, warning colors, and symbol explicitness can affect waming effectiveness and hazard perceptions. This study assessed the impact of two warning colors, two warning sign types, and two levels of symbol explicitness on college student behavior. Scaffolding was erected in front of a building to simulate a construction area, and warning signs were placed on one door instructing individuals to use an alternate exit. Warning effectiveness was assessed by comparing transformed proportion data based on the number of people exiting the building. The presence of a sign significantly altered traffic patterns. The traffic patterns did not vary as a function of warning color, sign type, or symbol explicitness. Warning signs play an important safety role by communicating hazard information. The three-panel warning uses signal words, colors, symbols, and text to describe hazards and mitigating actions. Although many of the warning sign components have been studied mdividually, little research has considered how elements combine to influence behavior in natural settings. The present study considers the influence of signal words, color, and symbol explicitness on the behavior of individuals in a simulated work environment. Signal Words Early research (Bresnahan & Bryk, 1975) revealed that signal words increased the perceived hazard of warning signs. More recently, Wogalter, Jarrard, and Simpson (1992) concluded that signal words increased the hazard perception of product labels when compared to labels without a signal word. Chapanis (1994) compared the apparent level of hazard for three different signal words: CAUTION, WARNING, and DANGER. He determined that DANGER represented the highest perceived hazard, followed by WARNJNG, which was perceived as an intermediate hazard, and CAUTION which conveyed the least hazard of the three signal words. Color Color, just as signal words, can be arranged along a continuum of perceived hazard. When examining the interaction of color and signal word,