By plane
Troy is located approximately 30 miles north of Detroit Metropolitan Wayne County Aiport which is a major hub for Delta Air Lines and also has international service operated by Lufthansa, KLM, Air France, and Royal Jordanian. Shuttle service to Troy is available but is expensive roughly $30 per person and a taxi to Troy could run as much as $60. Therefore, it may be less expensive to arrange someone to meet you at the airport, or rent a car; even if you don't intend on driving much once you are in Troy.
For those who seek a bargan, or if you live relatively close to the area try flying into Flint Bishop International Airport. Fares are somewhat lower than what you would expect at Metro Airport, and the drive time into Troy is about the same about 1 hour.