This report presents a human factors study conducted to examine the feasibility of employing graphics to aid message display on dynamic message signs (DMSs). DMSs have been increasingly used by highway traffic management to provide drivers with real-time traffic information and advice. These signs, often mounted on overhead sign bridges above arterial highways, are capable of displaying extensive textual messages which could pose a challenge to drivers' comprehension while driving at high speed. Since graphics are usually considered a more effective means of communication than texts, graphic-aided DMS messages were developed and tested in this study. A questionnaire survey and a lab simulation were used to assess the effects of these messages on human drivers. The former collected drivers' preferences regarding the design of graphic-aided DMS messages while the latter measured drivers' response to a selected group of test messages. A total of 127 subjects participated in the survey where they selected message designs and displays per their preference. Forty-eight subjects, from three age groups with balanced genders, partook in the simulation experiment where they made responses to simulated DMS stimuli with or without graphics. Results obtained from this study would help guide the development of graphic-aided messages to be used on US highways.