This paper presents the results of a legibility study of 9-in. and 10.6-in. letters on changeable message signs (CMSs) with light-emitting diodes. The study, conducted in Dallas, Texas, consisted of 60 subjects, demo-graphically balanced with respect to age, gender, and education. The subjects drove a test vehicle as they approached CMSs with one of the above letter heights. Study administrators recorded the distance from the sign at which the participant could correctly read a three-letter word. Data were recorded for three trials on each of the letter heights for each participant. Data were collected during daylight (sun overhead) and nighttime conditions. The 85th percentile legibility distance for the 9-in. letter height was 228 ft for daytime conditions and 114 ft for nighttime conditions. For the 10.6-in. letter height, the 85th percentile legibility distances were 324 ft for daytime conditions and 203 ft for nighttime conditions, respectively. The 85th percentile legibility distances for each letter height were used to estimate available viewing times under various approach speeds. These available viewing times dictate the units of information that can be presented on a CMS of a particular letter size.


    Access

    Download

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Legibility Distances of Smaller Letters in Changeable Message Signs with Light-Emitting Diodes


    Additional title:

    Transportation Research Record: Journal of the Transportation Research Board


    Contributors:


    Publication date :

    2005-01-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Legibility Distances of Smaller Letters in Changeable Message Signs with Light-Emitting Diodes

    Ullman, Brooke / Ullman, Gerald / Dudek, Conrad et al. | Transportation Research Record | 2005


    Legibility Distances of Smaller Letter Light-Emitting-Diode Changeable Message Signs

    National Research Council (U.S.) | British Library Conference Proceedings | 2005


    Night legibility distances of highway signs

    Allen, Terrence M. | TIBKAT | 1959


    Effects of Full Matrix Color Changeable Message Signs on Legibility and Roadway Hazard Visibility

    Chrysler, Susan T. / Carlson, Paul J. / Brimley, Brad et al. | Transportation Research Record | 2017