[Noah930]

It's not just p/u drivers. It's just that p/u are more likely to be carrying poorly secured cargo.

I was returning to Boston from the Cape once on my motorcycle. 4 lane divided hwy (2 lanes in each direction). There was a car with a mattress tied to it's roof. Maybe it looked sturdy in someone's driveway, but the leading edge of the mattress was catching air at highway speed and was levitating motorboat-style off the roof. Fortunately whatever twine the guy used held. But I kept thinking that if that line gave way, it would not be good for traffic behind (particularly for me, on a motorcycle). I remember it being very uncomfortable. I wanted to pass mattress guy to get out of harms way (plus he was doing about 55 mph), but had to pick a spot as he was in the fast lane glacially passing other traffic. I was afraid the mattress would come flying off at any moment so I didn't want to get too close (what are the aerodynamic properties of a mattress at 55 mph, I wondered), yet at the same time there was other car traffic behind me that wanted to pass mattress guy, too. All the while this guy's driving along, blissfully unaware that the mattress is hovering about 2 feet off his windshield header.