mono

The complete set of symbol signs developed by AIGA in collaboration with the U.S. Department of Transportation and released from 1974 to 1979, is available online in EPS and GIF formats (via Jeffrey Zeldman).

Designed for "the crossroads of modern life" — airports, train stations, and large international events — the signs were in effect adaptations or redesigns of existing individual symbols, gathered from around the world. The result was the first system of symbols that "communicated the required range of complex messages, addressed people of different ages and cultures and were clearly legible at a distance."

While most of the 50 signs convey their intended meaning with impressive clarity and legibility, some work less effectively. The most notable of these is the symbol for 'Information', shown above. The encircled question mark is visually striking, but confusing. Its main problem is that it focuses on what its audience has (questions, problems) instead of what it needs (information to answer questions and solve problems). This way of identifying with a present and undesirable situation seems to work better in advertising. The confusion is even more apparent when the question mark is combined with another symbol, as in the sign for 'Hotel Information', shown below.

The sign seems to communicate a troubled, sleepless man, rather than a place to consult when looking for hotels.

It is interesting to note that in their efforts to find powerful visual symbols, the designers seem to have overlooked the most obvious choice: the letter i. The i symbol is simple, intuitive, and, unsurprisingly, seems to have become internationally favored over the question mark. Perhaps there is an interesting story behind the design process?

See also Design Observer's The Graphic Design Olympics.