Caution Flags
If you don’t have any caution flags to attach to the wide load you are carrying down the street, consider using some local vegetation. It seems to be working quite well for this gentleman.
The long thin posts he is carry would definitely be tough to see as you whiz by on your motorbike, but with these leaves attached it is quite easy. No, it’s not a good solution for night time driving, but it worked just fine in the sunlight.