What is the safest way to transport large amounts of fruits & vegetables?
I have less concern that you’ve mixed the fruit/vegetables together for that short period of time and more concern about the temperature at which you’re traveling for 4 hours. If none of the produce items are cut up, then a cool van/car should be sufficient to prevent deterioration. If any of the items are pre-cut (salsas, cut melons, packaged salads, etc.), then you’ll want to have them in a cooler right away to maintain lower temperatures for food safety reasons.