A cut slope failure on the Eskoriatza to Vitoria motorway in Spain

An interesting landslide occurred on a heavily modified slope on the Eskoriatza – Vitoria motorway in Spain on 27th November 2015.  The main failure event was captured on video, and is now on Youtube:

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I am impressed with the boldness of the highway authority in allowing one side of the road to remain open whilst this failure occurred.

Very helpfully, Fats Grasas has tweeted a sequence of images from a range of sources of the history of the slope.  This appears to be a Google Street View image from 2009:-

Eskoriatza – Vitoria motorway slope via Fats Grasas

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Whilst this is a Google Earth image, also from 2009.  The slope clearly has expensive treatment, but I am unsure as to what this is exactly.

Eskoriatza – Vitoria motorway slope via Google Earth and Fats Grasas

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Then this Google Street View image is from earlier this year:-

Eskoriatza – Vitoria motorway slope via Google Street View and Fats Grasas

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The slope has clearly undergone a major failure, part of which has spilled onto the road.  A Google Earth image, also from earlier this year, shows this failure in more detail:

Eskoriatza – Vitoria motorway slope via Google Earth and Fats Grasas

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It appears that this failed slope was being repaired, with substantial reinforcement and fill.  These slope strengthening works appear to have failed to generate the landslide last week.