A Swiss newspaper interviewed the workers - they said they liked it a lot more because a) they get to work regular hours but in the shade and b) they have more space, since the traffic goes above them. On a normal worksite they have barely a few metres, since the rest of the road has traffic flowing on it still.
It doesn't sound perfectly pleasant but are you suggesting the noise it too loud or what? Construction work has never been comfortable, and frankly I'm wondering if the shade of the bridge outweights the chaos of having an active roadway above head.
It's open on both sides, it's more like working under a tarp. They seem to be using proper PPE when appropriate, and not be covered in accumulated dust like mine workers.
