O.T. weigh station equipment

First "thing" I encountered was a box hung over the right most traffic lane and the right most traffic lane also had a steel plate across it under the box. So, something was under you as as you went under the box. Next were two more boxes this time hung between the 2 travel lanes and nothing under them. Actually I"m thinking now these last 2 were after the weigh station but I honestly don"t remember.

Sizes are hard to judge when your wizing under but they were traffic light size except they hung like a light laying on it"s back. The first one wide ways across the lane and the latter two wide way aligned with the lanes. I"m pretty sure they weren"t cameras.

I"m hoping someone will know what I"m talking about and can enlighten me.