23rd of June 2010 0
Which typefaces are used in traffic signs in your county, state or country? Do you have an idea?
Why is it you are so conscious of the typefaces you use while typing your work and yet you have never noticed the consistent and largely standardized typography of traffic signs all over the roads you drive through? Because that is basically why those specific font types are used: To attract the least attention and emphasize maximal concentration on the message, not the orthography.
US and Canada predominantly use FHWA alphabet series with specifics on letter-shape and spacing detailed in the Standard Alphabets for Traffic Control Devices published in 1945 by the Public Roads Bureau. These specifics on typefaces design have been updated to form Standard Highway Signs.
Initially traffic signs were in capitalized letters and digits but a revision in 2002 allowed traffic signs to include lowercase extensions. State departments and the federal roads agencies have since 1927 used uniform fabrication of straight-stroke letters in traffic signs.
Today however, rounded alphabets are used since the Pentagon road network constructed in 1942. Mixed-case alphabets are also standard especially on freeway guide signs an initiative experiment of the Caltrans, formerly California Division of Highways.
The idea behind the choice of typefaces used in traffic signs is to maximize on legibility. For example, all-uppercase letters are used for ground mounted traffic signs with reflective letters while mixed-case letters are used for externally illuminated and projected overhead guide signs. It is actually common for most local governments, road contractors and airport authorities to fabricate typefaces for traffic signs besides using the conventional FHWA series, if particular isolated cases require such fabrication for maximal legibility. Common variations include the use of Helvetica and Arial typefaces.
A lot of research has gone into finding out which typefaces are ideal to which traffic signs and in which environments. Some specific street sign like the left-turn prohibition sign which hangs from its gantry must be well lit for better visibility, especially at night or during inclement weather conditions.
Another example of how legibility determines the typefaces adopted, is the Clearview typeface, which was developed by U.S. government researchers exclusively as a typeface that improved legibility. It has since been adopted as the predominant typeface in poorly illuminated road areas by such states as Arkansas, Texas, Illinois, Pennsylvania, Michigan, Virginia, among others.