*Trucking Question* Has anyone heard of "rider insurance" or...

*Trucking Question* Has anyone heard of "rider insurance" or insurance for a passenger? Client: Owner/Operator of his trucking business took his daughter with him on a run. Trooper pulled him over and told him to have "rider insurance". Client is with progressive comm auto and they have not heard of this. Is this available through a BOP? Help - learning something new!