MDT Explains Large Dirt Piles at Construction Sites

Ever see those large piles of dirt at overpass construction sites around Montana? It looks like they're just sitting there and nothing is really happening, but that's actually by design.

The folks at the Montana Department of Transportation have put together a video to explain why these piles of dirt are an important step in the construction phase of building a bridge.

I've seen these piles of dirt and always wondered why they were there. Now I know!