The City Manager shall have authority to temporarily close any street or portion thereof when he or she deems such street to be unsafe or temporarily unsuitable for use. He or she shall cause suitable barriers and signs to be erected on such street, indicating that the same is closed to public travel. When any street or portion thereof is closed to public travel, no person shall drive any vehicle upon or over such street except when such travel is necessarily incidental to any street repair or construction work being done in the area closed to public travel or when the Police Chief allows such travel. No person shall move or interfere with any sign or barrier erected pursuant to this section without the authorization of the Manager.