Alternative Information Signs: an Evaluation of Driver Comprehension and Visual Attention

Abstract

The effectiveness of a traffic sign is collectively influenced by the sign’s understandability, legibility distance, glance legibility, and learnability; however, understandability has been repeatedly identified as a one of the most important measures of effectiveness. This study contributes to best practices for evaluating traffic sign understandability by using a variety of online survey questions and driving simulation tasks to assess the understandability of alternative Tourist Information signs in Oregon. To achieve this goal, the understandability of five alternative Tourist Information signs were first tested in an online survey with 142 participants, resulting in the identification of the four best-performing alternatives. The understandability of these alternatives was then tested in the OSU Driving Simulator with 42 participants. The “INFO” Sign was found to be correctly understood by 95.7% of the driving simulator subjects. The two “i” Sign alternatives had the second and third highest comprehension rates for driving simulator subjects with 72.8% for signs without a circular border and 75.4% for signs with a circular border. There was a statistical difference, at the 95% level, between the comprehension results of the online survey and the driving simulator test of the “?” Sign. However, it is likely that comprehension rates for the “i" Sign will continue to increase in the future due to its prolific usage in a wide variety of contexts.