Foundation elements for grade separations are subject to potential vehicular impact the use of steel sections in a trestle configuration in those potential impact zones is highly discouraged. Instead for grade separations, steel H piling can potentially be used under pile footings for interior bents or for abutments.

Foundation elements for stream crossings are subject to scour, drift impact and have a higher propensity for corrosion. For stream crossings, steel piling needs to be analyzed for potential corrosion over the life span of the structure and need to be evaluated for both axial and lateral loadings under the scoured condition. Steel piling that have been evaluated for the above conditions and found to be acceptable could be used for trestle bents. However, the steel piling must be coated to a minimum depth of 15 feet below the maximum predicted scour elevation. Steel piling can be used to support pile footings as long as the footing is embedded at a depth below the maximum predicted scour depth thus minimizing the risk of exposure. Piling used in a footing configuration must be coated a minimum distance of 15' below the bottom of footing. Piling can be used for foundation elements for abutments.