How Do They Make A Luge Track?

Every four years, the world turns its attention to the sports of the Winter Olympics.  One of the featured sports in the spotlight is the Luge - a glorified sledding track where sliders can reach top speeds of 80 miles per hour.

The competition is entertaining to watch.  If you've ever gone sledding yourself, your thoughts probably to something along the lines of "how do they make a luge track"?

This link gives you everything you need to know:  http://adventure.howstuffworks.com/outdoor-activities/snow-sports/luge1.htm