JD's Garage Micro
Before adding the last 2x4 on the skating surface (the one that will lie right below the coping on the finished ramp), I screwed in 3 supports for each section that would support my platforms. If I had not done this first, the 2x4 just below the coping would have been in the way and I would not have been able to screw in the platform supports from the front.
Below you can see where I pre-drilled the holes, and screwed in wood screws in preparation for attaching some additional platform supports.
After screwing in the platform supports, I prepared to screw in my last 2x4's (you can see the wood screws sticking out in the photo below as I prepare to do this).
I repeated the process for each section and when I was done I had two 4' wide transition structures for each side of the ramp (4 in all).