As I was working on a video project showing highway signs, I discovered the font used on highway and interstate signage is called “Highway Gothic.” You can download it for your own use here.
I also discovered the use of an new font called “Clearview.” It was thought to be a replacement for the tried an true Highway Gothic. After some promising research results on better readability it looked like it would be the new default. Interestingly, after reviewing the research, it appears that the better results on readability seemed to be caused by the fact that the signs using the Clearview font were newer compared to the older faded signs using Highway Gothic. In other words, they were not comparing apples to apples. So according to the Wikipedia article, Highway Gothic will remain the standard for the time being.