Thanks!!
Both actually. Optical and poor road building. I am in the process of rectifying it. I took the "concrete barrier" out, sanded the "pavement" remove some of it, pour plaster in the affected area, more sanding and now (eventually) will re-paint that portion (it will look like the real thing -like a patch-) and re-install the barrier (and improve on it). It's a big mess as you may imagine.
When I originally made the road I poured a mix of white-glue mixed in with very fine ballast (N scale) on top of the roadbed (cardboard)kinda like oatmeal consistency. When it dried it started to lift. Not as bad a the pictures but bad enough.
Will post more pictures as I get going..