This image is from a collection commissioned by the United States Department of Transportation and designed by AIGA. SVG by <a href="//commons.wikimedia.org/wiki/User:Doodledoo" title="User:Doodledoo">Doodledoo</a>.
<a href="//commons.wikimedia.org/wiki/User:Cmprince" title="User:Cmprince">Cmprince</a>
2006-02-19
Available <a rel="nofollow" class="external text" href="http://www.aiga.org/content.cfm/symbolsigns">here</a> as GIF.