In law, is a hired Transporter an Agent of the Hirer?Can we possible impute the Transporters negligence on the Hirer?
Without any research, generally no. It is unlike what is formerly known as the Master-Servant relationship, employer- employee.
While at times the Master was responsible for the actions of an employee, called basically, Respondeat Superior, I believe this trend is outdated to a certain extent, of course, state specific.
Generally, the action would have to be within the "course and scope" of employment to impute liability to the Employer under a basic Law of Agency theory.
Third party agents are generally not representative of the hirer to establish a joint or several liability.
I can't be any more specific without research. I have read some cases in the past at the law library, but can not remember a definite outcome.
You can research some selected terms; Repondeat Superior; Law of Agency, + subcontractor; etc.