Whether its billboards, busboards or transit, why do companies insist on cluttering their ads with to much information.
And in some cases the print is to small to read. Keep in mind how high up billboards are. You don't want your print to look jibberish.
Be careful of the background colors that your copy isn't lost in it.
Rule of thumb: 5 to 7 words max and don't try and tell me a story. Before anything gets printed for goodness sake, use spell check!
Outdoor media does a tremendous job to reinforce the brand.