James M. Cox Dayton International Airport: Take Greater Dayton RTA Route 43 to downtown (Ludlow at 2nd); allow about 50 minutes and roughly $2. It is the sensible budget transfer, but service is limited—check the timetable against your flight. For late arrivals, luggage, or a group, use rideshare/taxi; downtown taxis have historically run at least about $30, and rideshare is usually more practical than a prebooked shuttle.
Dayton Trotwood bus station: Greyhound’s stop is in the western suburbs, not downtown, and local onward connections are limited. Arrange a rideshare or pickup rather than assuming an easy transit transfer.
Interstate 70 / Interstate 75: Dayton is fundamentally a drive-in city: I-75 passes through downtown and meets I-70 just north of town near the airport. Cincinnati is about an hour south; Columbus about an hour east on I-70. A car makes the aviation sites, Wright-Patterson, suburbs, trails, and day trips dramatically easier.