A plastic bag filled with shiet that was left on the side of a road or a highway. Trucker Mines are usually prepared very hastily in the sleeper part of the truck, then left on the side of a road. Trucker Mines are most often found on an open stretch of a road and where truck stops are unavailable. The term is mostly used by the highway cleaning crews and it can be found in their safety manual under "Handling Hazardous Materials".
"Hey man! Be careful with that bag. It could be a Trucker Mine"