I baked a three tier cake for my grandaughters third birthday. I had to travel around 125 miles to the party. I used dowell rods and boards to support the cake. that part seemed to work well.
when I placed the cake in the suv, i placed it in the back. i used the non skid shelving foam. the board that I sat the cake on did not move but the main bottom layer of cake was on a cardboard cake board that sat on the wooden board. the cake actually slid from the wooden board because of the cakeboard that the cake was on.

what suggestion would you have to this problem that i had. and also traveling that far with a cake? remind you that i am a newbie to this.

Oh no, that's terrible!

I do it two ways. I either put the cake board directly onto a non-slip mat. Or I will put a big new box onto a slip mat. Then I put bubble wrap on the inside of the box. Then I put the cake in the box.

I cut two of the corners of the box, all the way to the bottom. It allows a little access door to slide the cake in. Then I tape the edges of the box back up.

Secure the bottom cake cardboard to the base wooden board with either a smear of buttercream, royal icing, or a hot glue gun (it doesn't touch the cake). You must do this or you'll get sliding!

I'm sorry to hear this happened to your cake... My suggestion is to no stack the cake for travelling. I took a 3-tier wedding topsy-turvy to Vegas (1.5-2 hour flight?... don't remember), each tier, fondant covered with some decrations in its own catdboard box. Car, x-ray belt, plane, shuttle, elevators, etc... no problem. Assembled on site (brought some extra fondant, spatula, decorations, etc. for last-minute fixes).

i have certainly learned a lot from this experience. but that is what gives you the experience to know what to do the next time. thanks everyone for the advise. i appreciate everyone on cc.

I just transported a 3 tier square cake (3 hour drive) yesterday to a wedding. I was sitting on the cake base on top of my silverplated plataue! The only thing holding it in place was a few good dolops of piping gel...I had put this all in the refrig. the night before to set up. (The cake was fondant covered.) This held real well! If anything would slide, I would think that would! I placed it in back of my SUV, on an egg carton foam piece to prevent sliding around...
But, I will say, typically I like the idea of using a large smear of Royal icing. I think it holds the best.

A good loop of folded over duct tape works wonders! Never had a board slide with this in place!

If duct tape won't hold it, it ain't worth fixin'!