Until they reverse on a highway and kill a family. Being able to drive isn't where parent poster put the bar
Not reversing on a highway doesn't require reading, just driving sense.
And whole lot of people have done stupid shit like that while perfectly able to read, many even with masters and PhDs.
I don't see what reading has to do with knowing not to reverse on a highway. It's not like they put up big glowing signs that say "wrong way" like in a video game.