You can't drive down the street in the mainland U.S. without coming across a billboard or advertisement of some kind. These advertisements are part and parcel of everyday life - but not in Hawaii. Billboards are actually illegal in Hawaii and have been for many years. The people of Hawaii don't believe billboards to be in keeping with their beautiful and natural surroundings, so they've decided not to allow them.
Hawaii isn't the only state in the U.S. to do such a thing, though. What you might not know is that Maine, Alaska, and Vermont have also followed in the same footsteps and banned billboards.