This was sent to me by the wonderful Weebles Thank you! I found that I should have used cakes with a 4" difference (14-10-6) because I wanted items to sit on the road... The following works great for getting your inclines.
First, to make the road look even make sure the layers are graduated evenly. For instance, for a 2" wide road and starting with a 14" pan, the next layers would be 12", 10", 8", etc.
I did stacked construction and had ALL the cakes stacked before I carved the road. The very bottom layer (your 14" layer) will not get carved at all.
On the next layer up, is where your road will make it's climb to the next tier. You will only be cutting the inclines, it isn't necessary to carve anything else. You will make only 2 cuts for each incline.
To make it easier you can stick toothpicks in the cake to mark where you will cut. Starting at the VERY bottom of that tier put in a toothpick in the side (flush with the top of the tier underneath). 1" to the right of the first toothpick put in another toothpick but make it about 1/2" up from the bottom of that cake. Put the next toothpick 1" to the right of the last toothpick and 1/2" higher then it (so that toothpick is about 1" up the side of the cake). Keep going like this - putting a toothpick every 1" over and another 1/2" higher, until you reach the top of the cake.
If you stand back you'll see that you have now marked the incline of the road! You can play with the toothpicks a bit to even things out or whatever. Now you are ready to mark for your second cut.
Look where you put in the very last toothpick at the top of that tier (the highest one sticking out from the side of your cake - it should be flush with the top) - 2" back from that toothpick, go across the top of that tier and stick in another toothpick (It will be sticking straight up from the top of that cake and right up against the next higher tier).
Now, look at the very first toothpick you put in the cake (the one that you have sticking out from the side, at the bottom of the cake) - from there, go straight up to the top EDGE and stick in a toothpick right at the edge and sticking straight up.
Now you are going to stick toothpicks between the 2 that are sticking straight up on the top of that cake. You want to make pretty much a straight line between the 2 toothpicks but SLIGHTLY curve the line of toothpicks to copy the outside edge of the cake.
What you should have now is toothpicks sticking out from the side of the cake going from bottom to top and toothpicks sticking straight up from the top of that cake that start at the outside edge and taper in 2" from the outside edge of the cake - right up against the side of the next tier.
Now you are ready to make your 2 cuts! Start with the side cut. Take your knife and start at the top of the cake (at the highest toothpick that is sticking out from the side). Gently slice down towards the bottom toothpick - following the toothpicks on the side - as you move towards the bottom of the cake don't cut into the cake as far.
Now make your top cut. Start at the toothpick that is at the OUTSIDE edge of the cake sticking straight up. Cut down through the top of the cake and follow the toothpicks that are sticking straight up. As you make this cut DO NOT cut any lower then the toothpicks that are sticking straight out from the sides of the cake or your road will get cut off the cake! Your cutting will be straight down but the cut will not reach the bottom of the cake ï¿½ it will follow the depth of the toothpicks that are sticking out from the sides of the cake.
Now take out the slice of cake and voila! you made your first incline!