Detroit-Toledo - Detroit-Toledo Transportation Co. was the first intercity bus company operating between those cities, operating through Wyandotte. Acquired in 1924 by Detroit United Railway, and consolidated into newly acquired subsidiary Highway Motorbus Co. In 1926, two bus companies, Interstate Stages and Detroit and Toledo Trackless Coach Co., introduced competing bus service between Detroit and Toledo. Interstate Stages operated nonstop, while Detroit and Toledo Trackless Coach Co. operated more locally via Telegraph Rd. In 1927, those two companies were acquired by Detroit United Railway, and consolidated into Highway Motorbus Co.
Highway Motorbus Co. - In 1922 began operation with intercity bus service from Detroit to Ann Arbor and Jackson along Michigan Ave., and from Detroit to Lansing and Grand Rapids along Grand River Blvd. Highway Motorbus Co. was acquired by Detroit United Railway in 1924 as a subsidiary.
White Star Motorbus Co. - In 1923 began operation with intercity bus service from Detroit to Flint along Woodward Ave., and from Detroit to Port Huron along Gratiot Ave. Acquired in 1924 by Detroit United Railway as a subsidiary. Also acquired in 1924 was Wolverine Transit, which had operated a local route from Detroit through Warren to Disco, probably via Van Dyke Ave. Wolverine Transit route replaced in 1927 with White Star Motorbus Co. route operating north to Imlay City, replacing discontinued interurban railway route. Successor Greyhound service from Detroit to Port Huron for a while was subsidized by SEMTA, but discontinued by Greyhound in 1983. Replacement service was operated by Tower Bus Co, which operated for a few years longer.
Ecorse Rd. - Intercity bus service introduced in 1926 via Ecorse Rd. between Detroit and Ann Arbor, by Detroit United Railway subsidiary Highway Motorbus Co. A competing company Pierce Motor Bus Co. later introduced bus service over same route. But in 1927, Detroit United Railway acquired Pierce Motor Bus Co. as a new subsidiary.
Outer Belt Transit Line - In 1922 began operation with bus route between Pontiac and Walled Lake. In 1925, route extended to operate from Mt. Clemens through Pontiac, Orchard Lake, Walled Lake, Farmington, Northville, Plymouth, to Ann Arbor. Acquired in 1927 by Detroit United Railway as a subsidiary. In 1928 became part of Eastern Michigan Motorbuses, with Pontiac to Mt. Clemens segment sold to Pontiac-Mt. Clemens Coach Line. In 1941 became part Great Lakes Greyhound Lines. Route sold in 1951 to Valley Coach Lines, in 1952 to The Bee Line Inc., and in 1979 to Tower Bus Lines. Route discontinued in 1987.
Ypsilanti-Saline - upon abandonment of interurban railway service in 1925 over this branch, replacement bus service operated by newly formed Detroit United Railway subsidiary People's Motor Coach Co.
Southfield Road - introduced in 1925 between Detroit and Birmingham as an alternate route to Woodward Avenue, which was being rebuilt at the time. Discontinued in 1926 after Woodward Avenue project was completed.
Ford Factories - introduced in 1925 between the two Ford Motor Co. plants in River Rouge and in Highland Park, mainly via Livernois Avenue. Discontinued a few years later.
Schoolcraft Road - acquired by DMB from Brightmoor Transit Co. in 1925, serving an area which was soon annexed to city of Detroit. Annexation resulted in transfer of route to DSR in 1926.
Six Mile Road - acquired by DMB from unknown operator in 1925, serving an area which was soon annexed to city of Detroit. Became part of DSR in 1932. Six Mile Road was renamed McNichols Road in 1950.
Mt. Clemens Bus Line - served Milford, Walled Lake, Auburn Heights, Rochester, Utica, Mt. Clemens.
Warren Coach Co. - suburban served Detroit, Van Dyke, Centerline, Warren, Utica.