scope:

FOREWORD

The first edition of the LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals incorporates recent work performed under the National Cooperative Highway Research Program (NCHRP), specifically NCHRP 10-80, and other research efforts including state-sponsored activities. These Specifications address:

• Division I on design,

• Division II on fabrication, construction, and

• Division III on inspection, and asset management.

Where possible, these specifications incorporate other AASHTO documents, specifically, the AASHTO LRFD Bridge Design Specifications, AASHTO LRFD Bridge Construction Specifications, AASHTO Manual for Bridge Evaluation, and AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing.

The design specifications are founded upon the Sixth Edition of Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals which incorporate a wealth of research, engineering practice, and long history of satisfactory performance for the vast majority of structures. Based upon NCHRP Report 796 (2014), LRFD calibration, and current research for both loads and resistances are incorporated. Resistances include several specifications associated with improved detailing for fatigue performance. Additionally, new sections on Fabrication, Construction, Inspection, and Asset Management are based upon best practices. These areas are evolving as agencies gain more experience with inspection and management of their ancillary structure inventories.

The design specifications provided in Division I are based on the LRFD methodology and are intended to address the usual structural supports. Requirements more stringent than those in the Specifications may be appropriate for atypical structural supports. The commentary is intended to provide background on some of the considerations contained in the Specifications; however, it does not provide a complete historical background or detailed discussions of the associated research studies. The Specifications and accompanying commentary do not replace sound engineering knowledge and judgment in design, fabrication, construction, inspection, or asset management.