(1) The contractor shall place adequate barricades to protect the public when there is a potential hazard due to the contractor's operation. The placing of barricades or additional barricades may be required at any time by the director of public works or planning and traffic engineer.

(2) When necessary for the public safety, the contractor shall employ flag persons whose sole and only duty shall be to control traffic around or through the construction site. The use of flag persons may be required by the director of public works or planning and traffic engineer.

(3) The contractor shall not impede rush hour traffic on arterial, collector or feeder streets, mornings or evenings. No construction shall be performed and all lanes shall be open to traffic during the hours of 7:00 a.m. to 8:30 a.m. and 3:30 p.m. to 6:00 p.m. These streets are shown on the city comprehensive street map (Dwg. No. TR 500-38) available in the office of the director of public works.

(4) The contractor shall not close more than one block of any residential street at any time and then only if approved by the director of public works.

(5) Where it is necessary to obstruct traffic during rush hours or on an arterial, collector or feeder street, where it is not possible to maintain at least one lane of traffic in each direction, an alternate detour or traffic flow plan shall be submitted to the director of public works three full working days prior to starting construction. The detour of traffic flow plan shall include placement of all barricades, signs and flagmen, plus the area of construction. This plan must be approved by the director of public works before a permit will be issued. The contractor shall notify the director of public works or planning and traffic engineer at least 24 hours before the implementation of the approved plan. The contractor is responsible for notifying the police and fire departments 12 hours prior to the closing or detouring of any street. (Code 1979, § 34-49)