The BYOB planner estimates supplies, but it does not decide whether outside beverages are allowed. Policies vary by city, route, operator, vehicle, event type, venue, and passenger age. Always confirm the rules before the event.
Ice and cooler needs depend on weather, trip length, drink type, and how many people are actually drinking. Use the output as a shopping-list draft, then adjust for your group and venue plan.
For stadiums, concerts, wineries, breweries, and venues with strict entry rules, check whether outside items can stay on the vehicle or must be left behind. Written confirmation prevents awkward day-of problems.