I have a wedding cake due tomorrow that I am working on now. I will be traveling about 20 miles with this cake to the venue and it will already be assembled (no room or ability to assemble it there with the atmosphere). I have poly dowels to place into each tier to hold up the weight of the cake above it. I know the procedure for doing this. However,my question is regarding a dowel (or dowels) for support of not allowing the tiers to slip and slide off of one another. I am NOT comfortable with doweling a center rod down the middle of all of the cakes, so I was curious as to whether I could place a dowel every 2 tiers.. For examples, tiers would be tier A, B, C & D; could I place a wooden dowel through tiers A & B and then place a dowel between tiers C & D? Rather than going through all the tiers at the very end?

Sure...But make sure that the cake has been refrigerated and is transported cold, and that will do more to keep it from moving than a center dowel will.