If you drive in spite of the flow if traffic, you are a danger, plain and simple, in which case this argument, "I drive the speed limit in my truck for SAFETY" is really specious. Also, the principles involved are no different for a car vs truck; methods, maybe, but not principle. To compensate for the difference, you must increase following distance, not necessarily reduce speed; I can't drive a package car like I drive my personal car, I have to allow myself room for error. In a tractor-trailer, have to give yourself even more room for error. But that doesn't mean doing 54 when everyone else is doing 65. It's rather selfish.
And one thing I like about NJ: they actually give tickets to people WHO GO TOO SLOW! They understand the concept of traffic flow: not too fast, not too slow.
Those who got ticketed being part of a group doing more than the limit: did you ever meet with a judge? What did he have to say?