Signs of the Times - October 2017 - 34
NUTS + BOLTS
When modifying existing sign
structures, all proposed details
must be evaluated and approved
by professional engineers.
structures including signage.
Section 11 (Fatigue Design) of
AASHTO's Standard Specifications
for Structural Supports for Highway
Signs, Luminaires and Traffic Signals
incorporates comparisons of relative
fatigue resistance among various,
common types of structural connections (welded and
AASHTO ranks the durability of these structural
connections according to stress categories that range in
descending order from "A" to "E." Section 11 also incorporates drawings identifying the most common types of
structural connections, thus enabling sign companies and
their engineers to make informed choices when creating
designs for outdoor structures.
SIGNS OF THE TIMES
Familiarity with these guidelines is useful in every phase
of outdoor sign projects, from manufacturing to installation and maintenance. Particularly when modifications
are proposed for existing structures such as replacing old
signs or installing additional signs, preliminary evaluations
and approvals by professional engineers are essential. In
these cases, the structures' original design specifications
must be referenced by project engineers to determine the
suitability of proposed modifications.