Use AirRide, a service by AAATA in partnership with Michigan Flyer. Multiple trips are available every day, year round. All AirRide trips serve AAATA's Blake Transit Center at 5th Ave & William St in Downtown Ann Arbor (near Ann Arbor Public Library). It serves the Kensington Court hotel (near Briarwood Mall) when Blake Transit Center is inaccessible (e.g. during home football games, Thanksgiving, any event that detours buses).
For schedules and fares, visit the AirRide website