The traffic engineer is authorized, when because of temporary detours or other emergency it would be impractical and a hazard to require vehicles to stop at an intersection where stop signs have been erected pursuant to this title, to either remove such signs or so cover them that no portion of the word "stop" remains visible. At the termination of such emergency the traffic engineer shall restore such signs or uncover such signs unless otherwise determined by the city council. (Prior code § 67606)