Abstract: The deployable stop sign for use with a traffic light during power loss comprises an enclosure, a traffic sign, a weight, a pair of electromagnets, and a sign retractor. The deployable stop sign for use with a traffic light during power loss may be coupled to a span wire or other structure supporting one or more traffic signals. A loss of power may deploy the traffic sign by deenergizing the pair of electromagnets and releasing the weight which may pull the traffic sign out of the enclosure. A restoration of power may energize the sign retractor to pull the traffic sign back into the enclosure and may energize the pair of electromagnets to hold the traffic sign within the enclosure.