Create roads out of separate curves

Hello everyone,
I am in the process of trying to make a road in a series of non-consecutive curves.
Let me explain: the yellow curves in the image (where the road should be) are each built separately by intersecting different curves all across the model. What I’d like to do is to create a road following the highlighted area. Problem is, since it’s not a whole consecutive curve, Rhino doesn’t extrude the surface.
Any suggestion on how to make it?
Thank you