These things aren't unheard of. The main A625 road that ran via the Hope Valley and Castleton to Chapel-en-le-Frith slid away altogether in the 1970s due to ground instability, despite repeated repair attempts. The land is still moving, even today and the road was permanently closed in 1979.
https://www.bgs.ac.uk/case-studies/m...de-case-study/