This speed limit awareness campaign for the New York City Dept. of Traffic dramatized how knowledgeable New Yorkers are about everything but the fact that the speed limit is 30 MPH.
Some unsettling guerilla outdoor also helped people understand the situation:
While this direct mail piece urged those who renewed their license to observe the speed limit, too:
Another DOT project I tackled at length was a bicycle safety initiative, where we used some unsettling techniques to remind cyclists to always wear safety gear and observe the rules of the road.