All along the motorway these things are mounted on the crash barrier between the lanes. There's one crash barrier for each direction of traffic and only one of them has these things mounted.
There's a couple of different colors, the darker ones fewer, no idea if that is on purpose or coincidence. There's some with white and red stripes at regular intervals.
I can't figure the purpose of these, does anyone know?
That would only be effective for blocking access to the lanes in the other direction, these are mounted in the middle of the motorway, not at the edges. But I think the high beam shield is perfectly reasonable as explanation.