I got those weird morning too. Part of the road I ride on in the morning has a freeway on ramp to 880. Usually at 4:30 am, I will see only one or two truck merging into the freeway only lane at the overpass. They give me space and not cut me off. One morning as I turn into that road at the intersection, I saw a convoy of 18 wheel semi waiting at their red light, all ready to go as soon as their light turns green. First thought was, where the heck did they all come from? Second thought: Do I want to put up with them when they catches up to me at the ramp?
I chose the sidewalk that morning

Only thing I can figured out is that they must have staged down in the other outlet parking lot down the street and it just so happens they all left at the same time and all were trying to get to 880 interstate before the traffic on the freeway start.