1. Municipal personnel, contractors or utility companies, while repairing or improving the streets of the city, or when installing, improving or repairing lines or other utility facilities in the streets, are hereby authorized, subject to control by the City Council, to close any street, or section thereof, to traffic during such activity and shall erect or cause to be erected, proper control devices and barricades to warn the public that such street has been closed to traffic.
2. When any street has been closed to traffic under the provisions of subsection 1. above and traffic-control devices or barricades have been erected, it shall be unlawful for any person to drive any vehicle under, over, around or through such traffic-control devices or barricades, or otherwise to enter the closed area (except that the provisions of this subsection 2. shall not apply to persons while engaged in such construction, maintenance and repair, to persons having their places of residence or business within such closed area, who may travel through such area at their own risk).
3. Whenever construction, repair or maintenance of any street, utility line or facility is being performed, and the street is not closed to traffic in accord with this section, the municipal personnel, contractor or utility company concerned shall erect warning devices for the public. Every person using such street shall obey such warning devices.