Towbars are a necessary fitting for many cars, but I am surprised that their development has not advanced to the point that they are not there when they are not being used. They can be very dangerous for pedestrians.
Twenty years ago plus one of our neighbours had a stroke. I took our neighbour on our other side to visit her at Caulfield Hospital. We were walking through the hospital carpark and at the very last second I could see the neighbour was about to walk into a towbar. There was no time to utter a warning. I just tried to grab her as she walked into it. I did not stop her but I did break her fall as she hit the ground. She was ok, just cut and bruised.
Several years later, my mother did the same thing. I was not there. She ended up in hospital for a day.
I am very conscious of towbars when I am out walking with someone. I watch them to see that they aren't going to walk too close to the rear of a car if there is a towbar sticking out.
Really, you would think that something could be done about such dangerous protrusions.