Sign Legibility

Sign Legibility
Link to USSC





  • USSC Sign Legibility Rules of Thumb
    Sign legibility covered in a simple to use rule of thumb format suitable for general application. Essentially synthesizes the more detailed analysis of USSC research into legibility and sign size determinants for both perpendicular and parallel signs. Click here to download PDF

  • USSC Guideline Sign Standards for On-Premise Signs
    Definitive research based approach to sign size, legibility, and height. Utilizes tables, charts, and equations designed to facilitate the calculation of perpendicular sign letter height and copy area, negative space, overall sign size, and sign height as functions of the speed of travel using factors such as message size, message scan time, viewer reaction time and distance, and copy area. Click here to download PDF

  • USSC Determination of Parallel Sign Legibility and Letter Heights
    Provides legibility values for signs parallel to a motorist's point of view which are inherently more difficult to read than perpendicular signs mounted directly in front of the motorist. By means of a mathematical model, letter heights necessary for adequate parallel sign legibility can be calculated. Also provides equations for calculation of parallel sign letter heights as well as height look-up tables for typical parallel sign scenarios. Click here to download PDF

  • USSC Computation Equations
    Algebraic equations for calculation of various aspects of letter height and sign size for both perpendicular and parallel signs under varied conditions; calculation of viewer reaction time for known sign sizes; and calculation of projection distance allowing for maximum projection limits at centerline of building. Also includces tabular USSC Legibility Index. Click here to download PDF

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