Filling the gaps in terrain model?

I have been trying this for a while know but I can’t figure out how to do this cleanly. I have a quite big terrain (this is a portion of it).

1.I create a mesh and and a draped version of it. I’ve tried to work with both mesh and and draped surface from point cloud. I then project the roads on to the surface
I read and been suggested to work with mesh, but mesh seems to be harder to cut. How do you go about making cutouts for projected roads?
2. Once I have projected the roads. I then go over the curves (that have way to many bumps) and trace over with CtrlPointCrv to make the roads flow more smoothly.
3. I use RebuildCrvNonUniform to make sure there isn’t too many control points. From the projected Crvs I then make a horizontal loft to get a the surface of a road.
4. I then srfblend the different segments were it is needed.
5. In order to close the gap and compensate for the slight difference in height of the surface of the terrain and the road. I extrude the srf road vertically both sides.
6. I then use split twice. Landscape cuts extrusion. Extrusion cuts landscape. This fills the gaps…usually.
But this takes some time and It is quite hard to fill in the gaps on a a bigger srf with alot of curved roads, slight differences in height.
I don’t really know how to go about this in a constructive manner of the whole process. This terrain will is not mainly done for 3D printing but will be used in further for presentation purposes. Maybe there is no really reason to close the gaps. But it is still quite enoying…

Right - if it is for images only, I’d say you could probably skip trimming these gap fillers - just send them through the terrain and leave them.