wireframe modelling

Hi there,

Just to share with you; a parametric model of the temporary cardboard bridge I designed fir Shigeru Ban at the pont du gard. The wireframe is supposed to go to the structural engineers directely.
It's my first attempt in grasshopper, so any comments on efficiency or further possibilities of the script are welcome.
I wish to implement a horizontal scale factor, for instance, so the structure becomes wider at the fixations only. How to do this?

greetz

p!m

pontdugard.ghx