Glatt, this photo came from my background image folder and has been flipped so that I can see the background image and my icons on the desktop.
CF
If there is no oncoming traffic any lane can be used by any vehicle. This also applies ( apparently ) around curves.
The divided road, two way traffic concept is lost here.
There are also only the physical limitations on things that might be transported by a given vehicle. If you can put it in or on the vehicle, then go with it. No flags or safety procedures apply.
The attached photo shows a tricycle carrying steel poles approx 20ft long. A tricycle is about 5 ft long.
There are examples such as this everywhere and yet I've only seen one accident. Amazing.