The Impact of Design Factors on Drivers' and Non-Drivers' Comprehension of Variable Message Signs

Area of Science:

• Human-Computer Interaction
• Traffic Engineering
• Cognitive Psychology

Background:

• Variable Message Signs (VMSs) are crucial for conveying real-time traffic information.
• Effective VMS design requires clear communication of event location and nature.
• Previous research indicates potential comprehension differences based on user experience.

Purpose of the Study:

• To investigate how driving experience influences the comprehension of VMS designs.
• To identify optimal VMS configurations for communicating temporary traffic events.
• To evaluate the effectiveness of current VMS templates.

Main Methods:

• A mixed factorial design experiment was conducted with 101 participants (51 non-drivers).
• Participants interpreted VMS displays with varying elements: pictogram, arrow, city name, complementary message, landmark order, and arrow function.
• The accuracy of identifying the event's location (before/after city) was the primary dependent variable.

Main Results:

• Drivers showed significantly better comprehension with a bottom-up landmark order and an explicit arrow.
• Non-drivers did not exhibit significant differences in comprehension across tested VMS configurations.
• Both groups experienced reduced comprehension with top-down order and generic arrows.

Conclusions:

• The G1c VMS template from the 1968 Convention appears ineffective for both drivers and non-drivers.
• Prior driving experience influences VMS interpretation, favoring specific designs like bottom-up with explicit arrows.
• Current VMS designs may not cater to the diverse comprehension abilities of all road users.