Nobody with a little bit of compassion laughs at stories like this. People read this with a bit of incredulity and a lot of compassion. We might make fun of Americans at times, but there's no humour here.
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.
Now imagine crash barriers made of steel wire. I don't know if they are still used in new projects, but there plenty of them around and a reason they were called cheese slicers.
Hold on a second ... how accurate is this technique and is it usable as a non-disruptable, world-wide, no infrastructure required GPS system?
Edit: Broke my own rule of not commenting before reading the damn article. Up to 2m accuracy, maybe there is something there. Would be a new Galaxy Positioning System if usable.
I suspected as much. I'm one of those socialist Europeans.