Map the passenger flow.
List hotels, offices, airport arrivals and the number of people moving at each time. A convention transfer with rolling arrivals needs a different plan from one executive dinner departure.
Identify the few deadlines that cannot move, such as registration, a keynote or a flight. Build the route backward from those times.
Give every group a clear meeting point.
Large hotels and convention venues may have separate transportation entrances. Put the exact door, curb or loading zone in the attendee instructions.
Use simple group labels when several vehicles are involved. Guests should be able to find the right ride without calling the organizer.
Create one communication chain.
Choose one onsite lead and one company contact who can approve schedule changes. Share the final manifest and contact list with the people who actually need it.
For airport transfers, monitor flight changes and keep luggage capacity separate from seating capacity.