I saw this in Southern NJ on Route I-295… What would this mean? It was a square sign showing the back of a truck with the number 102 in the center of the back of the truck…all of which was encircled by a green circle. What the heck does this sign mean to truckers? If it matters, this sign usually appeared below each I-295 route sign with few exceptions. - Jinx 
Perhaps it was the truck route for highway 102.
The green circle indicates approval (as opposed to the red circle with a slash through it indicating prohibited).
The 102 in the truck means that the road is valid for use by trucks that are 102 inches wide. New Jersey prohibits wide trucks from using state or county highways as “shortcuts” between certain destinations and the sign you see indicates that that road (an Interstate) is not prohibited to them.
http://www.state.nj.us/transportation/truck/truck_reg_071599.htm