Actually, it depends on WHERE you are, and in some cases WHAT you are driving.
For example, (unless they have changed the law since I quit driving commercially,) IF you are in an interstate commercial vehicle, (such as a semi,) you MUST NOT move the vehicle until instructed to do so by an officer of the law. (Federal DOT (Department of Transportation) regulations for common carriers in interstate commerce.)
Doing so could get your commercial drivers license revoked PERMANENTLY; (as well as a large fine and/or jail time in some states.)
It is ALSO accepted as "prima facia" evidence of guilt in the accident in several states.
Experience and knowledge from 20+ years in a big rig.