How do I carve a road that spirals around the cake starting on the bottom tier and going up to the next tier?

If you google carve a spiral cake and look at images you will see how it is done.  I use toothpicks to mark where the spiral is going down the cake and just slice into the cake.  If you look at the visuals you will get a better idea. :)

Thank you so much. I will do that.

http://cakecentral.com/a/how-to-carve-a-spiral-cake