I was hit by a commercial big rig. My lawyers say settle, saying that the offer is $52 out of a $55 K limit. Don't CDL's have a higher limit than 55?

My lawyer says that I have $32 thousand for medical bills that have been reduced to $20 thousand. He says that the insurance company has offered $52 thousand out of their $55 limit, meaning that if I did not want to settle we would be going to court for $3 thousand. I am wondering - it seems like the minimum for big rig commercial insurance should be bigger than $55 K. I don't want to be greedy but I am still injured and may need surgery, which will probably cost more than the $10 thousand I will clear if I settle. If I didn't settle would I really be going for $3 thousand? Is 55K the min?