I was eating in my car in a parking lot off 610 once many years back, and a truck carrying a trailer with a bracket holding a large spool of flexible duct much like that one went by on the feeder and hit a pothole, and the spool came loose and rolled off the back of the trailer. The ground was slightly sloped downwards towards the light at the overpass just a bit further down, and I watched the driver's surprise as the spool rolled past him and through the intersection as he slowed to stop at the light. Fortunately it just rolled past and into a ditch.