MxV Rail (formerly TTCI) investigated the optimization of crossing diamond foundation designs by monitoring a Class 1 railroad crossing diamond over three years (2018-2021) with two different diamond pad configurations. Acceleration measurements showed the two-layer pad configuration and solid foundational support produced lower magnitude acceleration values than the three-layer pad configuration or locations with poor foundational support. The two-layer pad configuration tested include under-tie pads (UTPs) and under-plate pads (UPPs). The three-layer pad configurations include UTPs, UPPs, and casting pads. Crossing diamonds present significant maintenance challenges for North American railroads because the wheels must cross flangeway gaps, resulting in impacts that increase crossing diamond foundation and component deterioration. Multiple efforts in the past have addressed crossing diamond and turnout deterioration from both a running surface1–2 and a foundation3–5 standpoint, resulting in the incremental improvement of crossing diamond life.2 This Technology Digest is a continuation of previous efforts and presents best-known…