One particulary notable thing about this movie is that there is no so much written words. Reckon on this, the title contains the word road and the audience might expect road signs with pronouns. Regarding on this, the filmakers' challenge was truly that.
At the time being I can not remenber any written word. Perhaps this movie is about procedure memory. Maybe a sign that appear is the one that it helps the driver to control the revolutions of the engine, the gearbox, there should be more but not so many.
In the film Prometheus something similar happens.