What is the penalty for traffic violation 39:8-1 in NJ?

I was pulled over the other day for expired inspection (39:8-1), which was roughly a month and a half past due. While looking up the penalties, I noticed that there is a $100-$200 fine and/or up to 30 days of imprisonment. The fine is not a terrible concern for me, but imprisonment for a non-moving traffic violation? Does this actually ever happen? My inspections have always been up-to-date prior to this. Was just wondering if this is something I should be seriously concerned about.