FHWA Series Fonts - History

History

The typefaces are officially defined by the FHWA's Standard Alphabets for Traffic-Control Devices, originally published in 1945 (reprinted 1952). Changes to the specifications were published in 1966, 1977, and 2000. The 2000 specifications differ from earlier versions in the shapes of a few letters and in the inclusion of lowercase letters for all alphabet series.

FHWA Series A, B, C, D, E, and F were developed by the Public Roads Administration (which later became FHWA) during World War II. Draft versions of these typefaces were used in 1942 for signs on the Pentagon road network. In 1949–50, as part of a research program into freeway signing carried out by the California Department of Transportation, Series E Modified was developed from Series E by thickening the stroke width to accommodate button reflectors for ground-mounted signs, while a lowercase alphabet was developed to allow mixed-case legend (consisting initially of Series D and lowercase letters) to be used on externally illuminated overhead signs. The lowercase letters, paired with Series E Modified, later became the basis of a national standard for mixed-case legend on freeway guide signs with the 1958 publication of the AASHTO signing and marking manual for Interstate highways.

Series "A" has been officially discontinued in the U.S., though it continues to be specified for certain signs in New Zealand. In 2004, the FHWA published lowercase letters for all of the typefaces and made changes to the Manual on Uniform Traffic-Control Devices, which allows their use.

Over the next few decades, the new Clearview typeface, also specifically developed for use on traffic signs, is expected to replace the FHWA series on some new signage.

Tobias Frere-Jones designed the typeface Interstate, based on the FHWA series, during the 1990s.