Surface selection after spliting

Hi,

I’m working in a terrain for 3D printing, and I already clean the terrain and the roads. So far no problem, now I’ve tried to select the roads after spliting the surface (I want to repeat the process with other terrains). I’ve used CLASH between a 3D extrusion of the roads with the already split 3D terrain and Roads. Afterwards, i’ve used CULLPATTERN & DISPACHT to select once the roads (in clash with the 3D extrusion) and once the remain terrain (no clash with the 3D extrusion).

And I have a few erros in the result, as you can see in the image.


The orange ones aren’t correct, and the blue one need to be selected.

I would like to find why it doesn’t work as planned, and a solution (or other way to solve it).

I let here the 3D model and the script, in case someone wants to try it.

Rhino Model & Grasshopper Script

Thanks in advance!!

MIB_Picapostes