A private dining quote for a multi-course French dinner in Las Vegas is usually thorough. It covers the menu course by course, the price per guest, the wine pairing, service, and the room itself, sometimes with a minimum the evening has to reach. It rarely covers the line that decides how the night ends for everyone at the table, which is how each guest gets home after four or five courses with a glass poured alongside every one.
Whoever books the room is acting as a host, whether the occasion is a retirement, a rehearsal dinner or an evening for clients. Hosts at home handle this without being told. They know who is staying in the guest room and whose spouse is driving. A restaurant evening hands the food and the wine to professionals and quietly leaves the transportation with the organizer, who is usually busy with a seating chart and a toast.
The practical version is short. Ask guests at RSVP whether they plan to drive, and treat the answer as information rather than a promise. Book cars or a shuttle for a little after the planned end, because a fixed menu runs long when the table is enjoying itself. Where the restaurant offers a non-alcoholic pairing, price it into the quote for anyone who says they are driving, so the person holding a valet ticket gets something composed for the food instead of a glass of water. Put the whole cost in the budget at the start, where it is a line item, rather than at the curb, where it becomes an awkward conversation.
None of that takes judgment away from the guests, and an organizer cannot drive for anyone. Some guests will leave early, wave off the car and walk to the valet stand anyway. Some of those evenings end with a traffic stop on the way home, and what follows is a legal matter rather than anything a dinner planner can fix. A guest in that position, or an organizer trying to help one the next morning, might look at a Las Vegas DUI defense practice such as Freedom First Criminal Defense and DUI Lawyers, which lists DUI and DWI defense among its practice areas. Naming it here is not an endorsement, and the publication offers no view on any case.
Most of an organizer's attention goes to the menu, the pairing and the seating chart, and those deserve it. The transport line takes less effort than any of them. It means one extra question on the RSVP, one booking with a car service or shuttle company, and one more email to the events coordinator asking for the non-alcoholic pairing to be priced in on the day the room is reserved.