This chapter describes how, for any type of highway sign to be visually effective, it must be readable. While this seems like a fairly simple objective to achieve, the information presented indicates that the ability of a driver to detect and read a sign is a function of numerous human, environmental, and design factors with complex relationships. For example, visual acuity, contrast sensitivity, visual field, and glare can significantly impact the driver's ability to see the sign and read its message. Furthermore, the basic design and placement of the sign can greatly impact the detectability and legibility of any highway sign. Features such as height, lateral offset, reflectorization, illumination, message design, font, case, letter height, border, and letter spacing are so critical that federal guidelines dictate these features to maximize the potential for a driver to see the sign within the highway environment. The photometric characteristics of the sign, including the internal contrast, luminance, and light design can also directly impact how well a driver sees a sign. And if all of these factors are not enough, the location of sign relative to the rest of the highway environment can either enhance its detectability or force it to compete with other signs and objects for visibility. Thus, the task of designing detectible, legible, and understandable highway signs is a challenge that continues to be refined as more is learned about their role in the highway environment and their interaction with the driver. Ultimately, we hope to provide critical information to the traveler that the can use in a timely manner to navigate safely through the highway environment.

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  • Corporate Authors:

    McGraw-Hill, Incorporated

    330 West 42nd Street
    New York, NY  United States  10036
  • Authors:
    • Garvey, P M
    • Kuhn, B T
  • Publication Date: 2004


  • English

Media Info

  • Features: Figures; References;
  • Pagination: 19 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00988749
  • Record Type: Publication
  • ISBN: 0071391223
  • Files: TRIS
  • Created Date: Apr 27 2005 12:00AM