Clearview, also known as Clearview Hwy, is the name of a humanist sans-serif typeface family for guide signs used on roads in the United States, Canada, Indonesia, the Philippines, Israel, Brazil and Sri Lanka. It was developed by independent researchers with the help of the Texas Transportation Institute and the Pennsylvania Transportation Institute, under the supervision of the Federal Highway Administration (FHWA). It was once expected to replace the FHWA typefaces in many applications, although newer studies of its effectiveness have called its benefits into question. Initial testing indicated that Clearview was 2 to 8 percent more legible in both day- and night-time viewing than the then-dominant Series E (Modified) on overhead signs, particularly benefiting older drivers, with a 6 percent increase in legibility distance. A design goal of Clearview was the reduction of irradiation effects of retroreflective sign materials. Reduced nighttime overglow or haloing was expected also to improve recognition rates for computer road sign detection. However, these tests also compared new signs in Clearview to existing, weathered signs in the existing Highway Gothic font. The new font's apparent legibility "was more due to the fact that older, worn signs were being replaced with nice, fresh, clean signs which were, naturally, more legible." Better testing also revealed that legibility was worse for negative contrast signs (dark lettering on light backgrounds) such as on speed limit and yellow warning signs. History The standard FHWA typefaces, developed in the 1940s, were designed to work with a system of highway signs in which almost all words are capitalized; its standard mixed-case form (Series E Modified) was designed to be most visible under the now-obsolete reflector system of button copy, which has since been superseded by retroreflective sheeting. The designers of Clearview sought to create a typeface adapted for mixed-case signage, initially expecting it would be based on an existing European sans-serif typeface. Instead, using a similar weight to the FHWA fonts, a new font was created from scratch. Two key differences are much larger counter spaces, the enclosed spaces in letters like the lower case "e" or "a", and a higher x-height, the relative height of the lower case "x" to the upper case "X". Smaller counter spaces in the FHWA fonts reduced legibility, particularly when the letters glowed from headlight illumination at night. Official acceptance Clearview was granted interim approval by the FHWA for use on positive-contrast road signs (light legend