As Defined by AASHTO, an EPA value (Effective Projected Area) is a coefficient used by the lighting industry to determine how much force a luminaire will apply to the mounting brackets or pole at a given wind velocity.  The map below is to be used as a general reference for the wind speed.  Brandon Industries believes that local authorities/engineers with specific knowledge of the application should make the final decision on the required design specifications.


The maximum allowable EPA is derived from:

  1. The maximum allowable bending stress at the welded joint between the pole and the base,
  2. The maximum deflection at the top end of the pole being ≤ 5% of the exposed pole length with a 100-lb force applied at the top of the pole, and
  3. The projected area of pole and sign combined

Reference ASCE 7-10 for wind forces. Exposure C category. Consult ASCE 7-10 for basic wind speeds in the desired site locations.

For poles located near ridges, escarpments, or axisymmetric hills please consult with an engineer for these applications.

Local codes and standards are to be reviewed and applied by others.