The alternative electric vehicle charging general service symbol from FHWA Interim Approval 13, intended to replace the electric vehicle charging general service symbol on the Electric Vehicle Charging sign (D9-11b) defined in the <i><a href="https://en.wikipedia.org/wiki/Manual_on_Uniform_Traffic_Control_Devices" class="extiw" title="w:Manual on Uniform Traffic Control Devices">Manual on Uniform Traffic Control Devices</a></i>.
Federal Highway Administration
<a rel="nofollow" class="external text" href="https://mutcd.fhwa.dot.gov/resources/interim_approval/ia13/index.htm">Interim Approval for Optional Use of an Alternative Electric Vehicle Charging General Service Symbol Sign (IA-13)</a><a rel="nofollow" class="external autonumber" href="https://mutcd.fhwa.dot.gov/resources/interim_approval/ia13/ia13evcaltd911bimg.pdf">[1]</a>