ASCE/SEI 7-10 exempts electrical raceways, conduit, cable trays, and bus ducts from seismic bracing requirements in Seismic Design Category C if Ip =1. Cable tray type matters in seismic design because stiffness, mass, joint behavior, and cable containment all affect performance. These codes mandate specific reinforcement measures to ensure that the system can withstand earthquakes. This is so even though the systems are typically not designed for earthquake. Since the facilities were located in a area of high seismicity, the cable tray system was required to be braced to resist seismic forces. Braces are typi-cally installed.