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In the preliminary research plan, it
was assumed that the comparison typeface(s) would be from an existing
sans serif typeface based on most probably a European example.
Though many typefaces were reviewed — Syntax, Avenir, Thesis, Frutiger,
British Transport, Normschrift, Univers, etc. — none provided
an effective comparison to the standard highway fonts based on
stroke, letter width, open shape of counters, and neutrality in
character. We desired a simple looking typeface, but one with character
and a subtle differentiation between letters to improve word recognition.
Metamorphosis of Design:
FWHA Standard Highway Alphabet E-modified to ClearviewHwy
Based on these requirements the project team began by designing
two mixed case typefaces that were similar in weight to FHWA Standard
Alphabets, Series D and Series E-modified. The letter designs were
prepared using a series of proportional templates that were not
based on other typefaces, but were designed with attributes to
aid viewing from a distance. Special emphasis was given to the
design of the most critical lowercase letters “a, e, and s,” the design
of the counters, the relationship of ascender to the lowercase “x,” and
the geometry of the stroke convergence in order to minimize halation.
The resulting product were two typefaces that were named Clearview-Bold,
a full width version, and Clearview-Condensed, a condensed version.
Once the final designs were developed, nearly ten years later,
the typeface was named ClearviewHwy ILLUSTRATE Box with e-m and
cv 5 D and Cv3.
The experimental design plan included legibility and recognition
tests to accommodate both the known and unknown components of guide
signing. Legibility is the point at which a viewer can read an
unknown legend based on identifying each individual letter and
reading the word. For guide signs or street name signs, recognition
is often more important because a viewer is looking for a destination
name. The recognition process is the marriage of the viewer’s
mental picture of a word and the physical word on the sign. Recognition
distances (seeking know destination name) with mixed case legends
are as much as twice the legibility distance (seeking unknown destination
name).
After an experimental design was developed by the research team,
subjects viewed actual sign panels on the Pennsylvania Transportation
Institute (PTI) test track. These studies, in which half of the subjects
were older drivers, were based on actual words with three distinct
patterns of ascenders and descenders, and with the necessary complexity
to test a viewer’s ability to recognize word patterns using
both Clearview and FHWA Standard Alphabets. Viewers were asked to
read signs from a car moving slowly toward the panels in the legibility
studies, or were asked to identify the position of a particular word
on a panel with three words in order to test for recognition.
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Subject recording response to computer simulation test for
word recognition |
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Experiment developed to test subjects speed of recognition.
Test was designed to reduce the number of variables needed
in an actual field test (track) environment. |
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Subjects in automobile recording distance at which test words
become legible on test track. |
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Testing for maximum legibility by increasing
or decreasing letterspace. |
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The effects of night brightness materials on
legibility during nightime viewing. |
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