scope:

The provisions of these load and resistance factor design specifications for structural supports for highway signs, luminaires, and traffic signals, hereinafter referred to as the Specifications, are applicable to the structural design of supports for highway signs, luminaires, and traffic signals (LRFD Structural Supports). The types of supports addressed in these Specifications are discussed in Article 1.4. The Specifications are intended to serve as a standard and guide for design, fabrication, construction, inspection, and asset management.

These Specifications are not intended to supplant proper training or the exercise of judgment by the Designer. They include only the minimum requirements necessary to provide for public safety. The Owner or the Designer may require the design, quality of materials, fabrication, construction, and asset management to be higher than the minimum requirements.

The design provisions of these Specifications employ the Load and Resistance Factor Design (LRFD) methodology. The factors have been developed from the theory of reliability based on current statistical knowledge of loads and structural performance, including materials properties.

Seismic design is not included in these Specifications, and such procedures should be prescribed by the Owner.

The commentary references other documents that provide suggestions for meeting the requirements and intent of these Specifications. However, those documents and the commentary are not intended to be a part of these Specifications.

These Specifications are the result of National Cooperative Highway Research Program (NCHRP) Project 10-80 and the corresponding NCHRP Report 796. These Specifications are intended to replace the sixth edition, Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals (2013).

At the discretion of the Owner, proprietary solutions may be considered. These solutions may address both new structures and the repair or rehabilitation of existing structures. Testing of proprietary solutions shall model actual conditions as closely as possible, and the test methods and results shall be published.

Where appropriate, the language and intent of the Specifications is kept the same as in the AASHTO LRFD Bridge Design Specifications and the AASHTO LRFD Bridge Construction Specifications. The following definitions are used:

The term "shall" denotes a requirement for compliance with these Specifications.

The term "should" indicates a strong preference for a given criterion. The term "may" indicates a criterion that is usable, but other local and suitably documented, verified, and approved criterion may also be used in a manner consistent with the LRFD approach to structural design.

In most cases, wind combined with other load effects controls the structural design.

The commentary discusses some provisions of the Specifications with emphasis given to the explanation of new or revised provisions that may be unfamiliar to the reader. The commentary is not intended to provide a complete historical background concerning the development of this or previous Specifications, nor is it intended to provide a detailed summary of the studies and research data reviewed