(a) The permittee shall protect with adequate and sufficient warning lights and devices any opening or obstruction placed in the street right of way. Warning lights and devices shall be placed in such manner as to be seen distinctly by all users of the street right of way at all times of the day and night. Whoever shall neglect to perform the duty imposed herein shall, in addition to the penalty provided by this chapter, be liable for all damages to persons or property caused by such neglect.
(b) Deposits of excavated material or any other obstructions placed in the street right of way about the work site shall be placed in such manner as to insure the least inconvenience to users of the street right of way. The opening and all obstructions shall be protected with adequate barricades during the time work is not in progress. The Street Commissioner may require that all trenches or other unfilled openings be covered by a metal plate sufficient to maintain uninterrupted vehicular or pedestrian traffic and may further specify the type and number of barricades as may be necessary to reasonably protect the public against injury to any person or damage to any property.