Variable Message Signage Content: Survey Test of Meaning and Simulation Test of Usability

Successful communication with motorists concerning the preseance and constraints of the roadway ahead is critical for improving safety and traffic flow in work zones. The content of messages presented on static and variable message signs (VMSs) is especially important given that drivers must detect, comprehend, and translate signage information while being preoccupied to some degree with the task of driving their vehicle. A survey study was conducted as a preliminary investigation into the information content of VMSs and other real time motorist information displays used in road work zones. Four VMSs were used in the survey. The subject pool consisted of 75 volunteers (approximate mean age=45 years) who stopped at a rest area on Interstate 35W (Northbound) just South of Rush City, Minnesota. Two questions were asked about each sign concerning meaning and delay of journey. Results showed that drivers could understand the content of a message, but could not always predict the consequences of the information. Variations of three signs from this study were adapted for use in the simulation experiment.