Analysis of drivers’ preferences toward content and message format of variable message signs during tunnel emergency evacuation: A case study of Niayesh tunnel in Tehran

In the event of an emergency evacuation of a tunnel, variable message signs are one of the tools available to tunnel operators to communicate with tunnel users and play an important role in guiding them. In this study, the primary focus is to determine the most appropriate message for variable message signs in terms of content and format for tunnel emergency evacuations. This study evaluates the responses of drivers to the visual comparison between variable message signs by using stated choice methods. Using a binary logit model, the results indicate that drivers prefer the text message “Turn off the car, exit the tunnel” in two lines on the right side of the sign along with the green image of the emergency exit on the left side. Therefore, it is anticipated that the findings obtained and their application at the time of the tunnel disaster will reduce the likelihood of catastrophic accidents and mitigate their consequences.