For a large conference, don't just maintain a name list — give each guest an explicit state.
For example: invited → confirmed → flight confirmed → vehicle assigned → driver confirmed → flight landed → driver met → delivered → complete.
Then the project owner sees not 100 names, but: how many people are not yet safely delivered.
Exception states should be flagged separately
For example: flight delayed, can't be reached, hotel changed, companion added, trip cancelled, driver changed.
A very important control metric
For large events, track in real time: Outstanding Guests = the number of guests whose transport is not yet complete.
For example, 100 guests: 82 delivered, 8 driver picked up, 6 awaiting landing, 4 exceptions. The project manager immediately knows the real focus is those last 4 people.
Why does this work?
Because a large event is not, at its core, vehicle management — it is: status management. Vehicles are just one resource. This is exactly why the management approach must change as an event grows from 20 to 200 people.