South Dakota reneged on a double-meaning, double-warning ad. All those doubles were made intentionally, according to the Huffington Post, who states that SD's "Highway Safety Office insists the double-entendre was intentionally inserted to get people's attention."
I don't see the problem, aside from yellow government officials. You had the idea (which was a good one, by the way); you apparently got approval from somebody's boss to go through with it; and you caught people's attention. Not only is it a good idea to warn drivers not to jerk the steering wheel when it's slippery outside, it's also a good idea to warn drivers not to jerk their driving post when it's slippery inside, and even worse when there's inclement weather going on.
Though maybe they did set a good example. How many government employees have you meant that publicly second-guess their own decisions?