Clearview Font on Negative Contrast Traffic Signs: Summary Report (0-4984-S)

The Clearview font was developed for traffic signs as the result of a program to increase the legibility and ease of recognition of positive contrasts sign legends while reducing the effects of halation (or overglow). Halation is a particular problem for older drivers and drivers with contrast sensitivity when letters use high brightness retroreflective materials. One component of the program was to identify ways to create a more effective typeface than the E-modified font used for destination legends on freeway guide signs. A second component was to compare the ease of recognition of mixed-case displays in lieu of all capital letter displays (Series D), and to learn if a mixed-case display would need to be larger than the comparable all-capital display for improved legibility and ease of recognition. When allowing a viewer to read the footprint of the world displayed in upper and lowercase letters similar to printed text, there is an increase in accuracy, viewing distance, and reaction time.