Ramy S. Ghebrial’s research while affiliated with Pennsylvania State University and other places

Although highly legible, the National Park Service's (NPS) Clarendon font produces sign legends that can be 10% to 20% longer than those depicted in conventional sans serif fonts. Placing these wider signs on narrow park roads and in urban historic districts can be prohibitive. To address this problem, a project was initiated to create a new NPS Roman-style (i.e., serif) font that requires less horizontal sign space than Clarendon while improving sign readability and retaining Clarendon's unique signature quality. The present study also evaluated a set of guide sign arrows to select the most legible for use on NPS guide signs. Three candidate typefaces were developed for daytime and nighttime field evaluation with 72 older and younger subjects. From the results of the evaluation, a fourth font was created and field tested with 12 additional subjects. Words created with the fourth font (NPS Roadway) were 5% to 11.5% shorter than those created with Clarendon. Further, subjects were able to read these words at 10.5% longer average threshold legibility distances than the same words composed in Clarendon. The relative legibility of 12 candidate guide sign arrows was evaluated in an outdoor field study. Forty-eight subjects participated in the daytime, and 32 subjects viewed the arrows at night. There were statistically significant differences in legibility distance among the various arrow shapes. The arrow ultimately recommended for use on NPS road guide signs performed 18% better than the FHWA "standard arrow."