1 research outputs found
Visual Perception and Understanding of Variable Message Signs: The Influence of the Driversâ Age and Message Layout
Variable message signs (VMS) are used to display messages providing upâtoâdate trafficâ
relevant information so that drivers can safely adapt their behavior in real time. The information
reported in a VMS should be brief but comprehensive to minimize perception time. The latter can
be influenced by the way the message is displayed. This study investigates how the different ways
of displaying the same message can influence reading time and the information perception process
at different driving speeds. Specifically, the following message characteristics are investigated: (i)
use of uppercase and lowercase letters; (ii) use of familiar pictograms; and (iii) use of less familiar
pictograms. Furthermore, as perception time typically changes with ageing, drivers belonging to
three different age classes are tested. The experimentation was performed by simulating a vehicle
passing along a straight road upon which a VMS displaying different messages was placed. Experâ
imentation results are analyzed using the KruskalâWallis test, Friedman rankâsum test and Welch
oneâway ANOVA, showing that: (i) the use of uppercase or lowercase does not seem to significantly
affect reading times; (ii) the use of pictograms that are not very familiar to habitual roadâusers can
be counterproductive for the perception process; (iii) elderly drivers always have greater difficulty
in perceiving the message than young or middleâaged drivers. The findings of this study can be of
help for traffic authorities to design the most suitable structure for a VMS so that its information
can be unequivocally and immediately conveyed to drivers