Judgment for plaintiff in personal injury suit is vacated and remanded, where: 1) a commercial vendor owes a duty of care to persons on or near the roadway who are injured as a result of the vendor's negligence in loading and securing cargo in a vehicle in a way that distracts the vehicle's driver; 2) the driver's negligence in driving under the influence of marijuana does not constitute a superseding cause as a matter of law; instead, the issue of superseding cause is one for the jury; but 3) the trial court abused its discretion in not striking, for lack of foundation, expert testimony that the driver in this case was a "chronic" marijuana user and thus unlikely to be impaired; and 4) because the driver's impairment was crucial to the allocation of fault between the driver and vendor, a new trial is required.