With a bowed curve here and a slight italic there, the font Dyslexie is designed to make reading easier for the 17 percent or so of the global population with dyslexia. Dyslexie, writes Design Decoded, adds subtle character to individual letters to make them easier to identify. In a small test with 43 participants, Dyslexie's creators found potential in their idea: It reduced reading errors compared to the control font Arial. Half of the study's participants were dyslexic.
Dyslexie's design intends to reduce the chance of dyslexic readers transposing or mixing up letters, confusing a "d" for a "b," for instance. Many letters are weighed down with a thicker base, while the loops on "d" and "b" are slanted slightly. The study wasn't able to prove that the font's design reduced switching errors, but it was a small sample, and further tweaks could help the letters stand apart more than they already do.
A font like Dyslexie could prove extremely useful in a classroom setting where kids are first learning to read. But the challenges of implementing it on a larger scale are interesting. Imagine if a font like Dyslexie made reading notably easier for people with dyslexia but remained easily legible for the average reader. If governments decided to implement that font into signage on a large scale, they'd have to spend hundreds of millions of dollars replacing old outdated signs with old outdated fonts.
Design Decoded writes that a simple font change in New York City, which changed street signs from all-caps to mixed case, cost $27.5 million. That was to replace 200,000 signs. On a national scale, that cost would skyrocket.
Thankfully, most signs don't rely exclusively on font for legibility or understanding--colors and shapes often tell us what we need to know. Drives in the United States associate red with Stop signs and Yields, just as they distinguish between the two thanks to the octagonal shape of one and the triangular shape of another. Those signs are tougher to mix up, but street signs may look awfully different 30 years from now.