SEATTLE -- They say you can't make a mountain out of a mole hill, but the Washington state DOT just made a road out of what is basically Styrofoam.

It's called Geofoam and it makes up most of the new ramp in front of Safeco field that goes over the railroad tracks.

"This is a light weight foam similar to the material that makes up a coffee cup, a Styrofoam cup," said David Sowers with the DOT. "But it's produced in large, very dense blocks."

Like Legos, the big blocks are cut with hot wires and glued together. It's been used to make roads in Europe since the 1970s in areas where the dirt is unsettled, resembling liquid.

And that's how the soil is under Royal Brougham Way. Not to mention, buried in that soil are huge, 100-year-old pipes. This foam will protect them, and since it's much lighter than traditional dirt and gravel fill, it will stop the ground from settling further.

Traditional fill that would be used for an embankment weighs about a 125 pounds per cubic foot when in place, and the Geofoam weighs about 5 pounds per cubic foot.

Once the pieces are in place, the whole ramp will be covered in a protective membrane coating, sealing it from potential fuel spills that would disintegrate the foam.

After that, it will be paved and made to look like a regular road, only with a surprising filling.

The DOT is also planning to use Geofoam again once work begins on the Alaskan Way Viaduct.