This research project focused on determining effective messages for encouraging drivers to leave their vehicles and evacuate a tunnel on foot; determining sign and marking formats that most effectively lead people to emergency tunnel exits; and determining the most visible sign and marking materials and technologies for use in highway tunnel environments. Focus groups were conducted to explore potential evacuation messages and delivery methods. Next, a simulated tunnel environment was used to test driver responses to emergency messages, and to test visibility and comprehension of selected emergency exit signs and markings, including the running man pictogram prescribed in the International Organization for Standardization’s 7010 guidelines. Results indicate that the running man pictogram was correctly or partially understood as indicating an exit by a majority of participants, and that a directional sign with the pictogram, “EXIT” text, a directional arrow, and distance in feet was correctly understood by virtually all participants. Visibility distances of tested internally illuminated signs were somewhat longer than those of tested photoluminescent signs; visibility for all sign technologies dropped sharply when viewed through smoke. The final product is a proposed set of guidelines for emergency exit signs, markings, and messages for use in tunnels in the United States, published as a brochure. .