TechEd Airport Shuttle Changes

At previous events, free shuttle transportation was offered to the airport on the final day of the conference. This year, airport shuttles are only available from noon to 4:30. Plus now you have to pay. Now it will cost $15 to use the shuttle service to the airport.

Mears is providing the shuttles, and you have to make reservations with them. I wonder if the change has something to do with them?