Specifications include, but are not limited to: 1.6 The Contractor shall inspect and maintain all contractor installed portable traffic control devices at least once during each twenty four (24) hour period. More frequent intervals of inspection and maintenance shall be made during periods of high winds or in areas where there is a continuing problem in maintaining the signs. Reports of all inspections with deficiencies shall be required and reported to Public Works. 1.7 The Contractor shall provide quality supervision of all crews during the performance of the service. Supervisors and flaggers/laborers must be able to converse in the English language, and shall be authorized by the Contractor to receive and carry out directives issued by Public Works. 1.8 On Portable Variable Message Signs, the message display shall utilize Light Emitting Diodes (LEDs), Flip-Disk, FlipDisk/Hybrid or LED Shuttered pixel for all matrix types (character, line and full). 1.9 All signs shall be NCFRP compliant and meet the requirements of MAG and MUTCD.