One time I was driving through California. They have that famous giant redwood tree with a road cut right through the middle of it. You probably have seen it in photos or famous pictures.
I was thinking about stopping but I really didn't want to drive a long way off the road and didn't have a decent local map. However, when I got to the exit it said "Drive Thru Tree Road". I obviously could figure that one out... just get off the road and there you go.
By the same token I love the express lanes in Chicago for I-90. They reverse every day, running out of Chicago in the morning and in to Chicago in the evening.
I used to live off the Armitage exit and now I live off the Ohio exit... and, coincidentally, out of the dozens of potential exits for the express lanes, there are only two - Armitage and Ohio - that made the cut.
It is a sign even I can follow...