23 C.F.R. § 630.1110
To provide for the continued effectiveness of temporary traffic control devices, each agency shall develop and implement quality guidelines to help maintain the quality and adequacy of the temporary traffic control devices for the duration of the project. Agencies may choose to adopt existing quality guidelines such as those developed by the American Traffic Safety Services Association (ATSSA) or other state highway agencies.1 A level of inspection necessary to provide ongoing compliance with the quality guidelines shall be provided.
1 ATSSA's Quality Guidelines for Temporary Traffic Control Devices and Features uses photos and written descriptions to help judge when a traffic control device has outlived its usefulness. These guidelines are available for purchase from ATSSA through the following URL: https://www.atssa.com/resource/quality-guidelines/. Similar guidelines are available from various State highway agencies.
23 C.F.R. §630.1110