Whenever the department determines upon investigation or re-examination that any of the grounds for re-examination are true, or that the safety of the person investigated or re-examined or other persons upon the highways requires such action, and it proposes to revoke or suspend the driving privilege of the person or proposes to impose terms of probation on his driving privilege, notice and an opportunity to be heard shall be given before taking the action.
Ca. Veh. Code § 13950