Wind Load Provisions in the 2001 Supports Specifications

The AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires and Traffic Signals (Supports Specifications) have been revised in its entirety through a major research project conducted under the auspices of the National Cooperative Highway Research Program (NCHRP Project 17-10). The new document was approved in 1999 by all state DOTs for adoption by AASHTO and was recently published in 2001. A major part of the revisions included new provisions and criteria for wind loads. These provisions differ considerably from those in previous editions of the specifications. A review of the changes in the wind load provisions of the 2001 Supports Specifications is given in this paper. These changes, which are primarily due to the adoption of a new wind speed map that is based on a 3-second gust, could result in a significant increase in the magnitude of wind pressure in hurricane areas and a decrease in inland areas depending upon location and structure type.