The FHWA XV Series typefaces were created as an alternative to the newly modified ClearView typeface system jointly designed by the Pennsylvania Transportation Institute (PTI) and the Texas Transportation Institute (TTI) and are a direct evolution of the FHWA Legacy typefaces first created by CalTrans in the 1950s. The FHWA XV Series typefaces were designed using the same recommendations outlined in an FHWA sign legibility study (1994) which suggested the need for mixed case alphabets and the elimination of visual massing of critical lowercase characters (a,e,s,i,l,w,y) on positive contrast (white lettering on darker background) signs. The FHWA XV Series typefaces also address many of the concerns which have been raised by various States and which are being lobbied to adopt the ClearView typeface system including:
1. contradictory research regarding positive contrast signing for median age drivers (18-49) for guide signs
2. preliminary research indicating a reduction in visibility and word recognition for negative contrast signing (black lettering on light background)
3. legibility issues for mixed typeface signing (i.e. FHWA Series and ClearView on one sign)
4. aesthetic and design continuity issues given ClearView in no way resembles any of the current or legacy FHWA typefaces
5. cost ($795 USD) per font seat
The FHWA XV Series typefaces are a comprehensive upgrade and redesign which (in summary) includes:
1. increase in lowercase character height relative to uppercase height
2. expansion of letterform counters to reduce halation and massing issues
3. a newly designed proportional spacing matrix based on only 12 values (9 base and 3 modifiers) for all 65536 possible character combinations allowing complete control over all aspects of inter-character spacing and proportional expansion/contraction of the upper and lowercase alphabets separately or in unison.
4. a new 1:4.8 stroke width to height ratio for the FHWA XV Series Em-P typeface increasing legibility on large guide signs
5. the complete redesign of critical lowercase characters (a,e,s,i,w,y)
6. the addition of positive and negative contrast versions of the typefaces
and many other improvements and modifications which are specified in the design manual.
Initial testing of the FHWA XV Series typefaces relative to ClearView and the current FHWA Series 2000 typefaces, indicates the FHWA XV typefaces have significantly increased legibility in the D,E and Em Series over the current FHWA 2000 US edition and equivalent legibility in the ClearView 3-W, 4-W & 5-W typefaces. Furthermore, although the design in the FHWA XV typeface was significantly modified, observers related that the signs using the FHWA XV typefaces "looked" the same as the FHWA 2000 and legacy 1966 and 1977 editions, thus preserving the visual look which drivers are accustomed to. Formal testing for the other FHWA XV typefaces are forthcoming. The final completion date for the project is first quarter 2006.