DDOT – The Detroit Department of Transportation provides local bus service within Detroit and parts of neighboring suburbs. Major routes like Woodward and Jefferson run every 10-20 minutes nearly 24 hours a day. Other routes are less frequent. DDOT also provides express shuttles for special events like the Freedome Festival Fireworks, AutoShow, and MotownWinterBlast.
SMART – The Suburban Mobility Authority for Regional Transportation provides local, express, limited, connector and paratransit within participating suburban communities in Wayne, Oakland and Macomb counties, including service to downtown Detroit.
Joint DDOT-SMART bus map (large pdf) – created by French graphic designer Aurélien Boyer-Moraes as DDOT and SMART do not currently work together to produce a joint map
The Detroit People Mover is an elevated automated guideway running a clockwise loop within the Central Business District of Detroit. DPM is run by the Detroit Transportation Corporation (DTC), a public corporation owned by the City of Detroit (and separate from DDOT.) It is especially popular with tourists and Red Wings fans.
AATA – The Ann Arbor Transportation Authority, or “The Ride” provides local bus service in Ann Arbor, Ypsilanti and parts of Washtenaw County.
TransitWindsor provides local bus service in Windsor and Essex County, Ontario, Canada, and also runs the Tunnel Bus, which takes passengers to and from downtown Detroit and downtown Windsor via the Windsor-Detroit Tunnel under the Detroit River.
CATA – The Capital Area Transportation Authority provides local bus service in Lansing and surrounding areas.
MTA – The Mass Transportation Authority provides local bus service and paratransit in Flint and Genesee County, with regional service to northern Oakland and Livingston counties.
Amtrak, also known as the National Passenger Rail Corporation, is a federally-owned company providing interstate passenger service across the U.S. Amtrak also provides commuter service in some cities, and operates the Acela express trains on the east coast between D.C. and Boston. Amtrak runs on railroads primarily owned by freight rail companies (Norfolk-Southern from Kalamazoo through Ann Arbor to West Detroit, CSX from Detroit to Pontiac), but also on some tracks owned by Amtrak (for example a stretch west of Kalamazoo that has been upgraded for higher speeds.)
Amtrak Michigan Services connect Port Huron, Detroit/Pontiac, and Grand Rapids to Chicago via 3 different routes.
Commercial Intercity Coach Services: Greyhound, Indian Trails, and MegaBus are private bus companies offering long distance travel between cities and across the country.
Other Relevant Agencies:
The Michigan Department of Transportation (MDOT) is the state agency in charge of all transportation in the state. A primary mission is to run state highways, but it also oversees transit projects and system.
The Southeast Michigan Council of Governments (SEMCOG) is the metropolitan planning organization for Southeast Michigan. It is responsible for coordinating regional transportation planning activities in the seven county region.