why are trucks driving in the middle lane(s)?

What about the well-being of the poorly-merging 4-wheeler? Physics is against them if they collided with a big rig.

 

In my truck I pick up speed as fast as possible and are lucky to get up to 45 mph. If I’m coming around a tight curve on ramp, much less. We don’t have a choice, as you know. Always a relief to look in my mirror and see that everyone is in the middle lane.