Hmmmm, that's as may be. Speculating (as ever) but, without any sign of the works, and with the driver in the cab, they are either setting up or pulling out. In either event I don't think it is unreasonable for roadworks to load and unload on the site.
As an obstruction, it's a fairly minor one, you have good sight of the oncoming traffic and it is at the cross over point. Bikes get by, pedestrians get by. Setting up traffic control ("Cyclists dismount" anyone?) would be far more of a pain for something that's not blocking anyone's progress, or endangering anyone.
Just think you may have been a little hasty jumping to indignation in this instance.