Sorry, I should have clarified that. Yes, a wagon and drag is just that.
I don't think they're any more dangerous than any other articulated vehicle, by which I mean keep well clear of them all if you're on foot or on a bike (or even in a car, sometimes). With a bendy bus, or a wagon and drag, the driver loses sight of around 20' of the vehicle (ie the length of the trailer) while it's turning, but with a conventional artic it's more like 45'. On the other hand, the back of an artic will swing out less than the back of a wagon and drag, as a rule. They were never banned here, but it used to be compulsory to have a driver's mate in the cab when you drove one, many years ago.
The other side of the coin is that wagon and drags can carry more volume than artics (30 pallets as opposed to 26), thereby cutting down on truck journeys, and they cause less road surface damage. But that's not really relevant to this thread.