Delta flies from Dayton to Detroit 4 times a day. Alternatively, Dayton RTA operates a bus from Dayton to Detroit every 30 minutes. Tickets cost $2 and the journey takes 13 min. Greyhound USA also services this route 5 times a day.
From Dayton taxi to Dayton airport, fly to Detroit airport, then line 261 bus to Detroit. 2 h 42 min $370. From Philadelphia & Harvard line 2 bus to Dayton Trotwood, OH then bus to Detroit, MI. 5 h 40 min $28. From Dayton drive to Detroit. 3 h 32 min $24.