Belleville-St. Louis Coach Co. - began operations in 1933 as Centralia-Belleville-St. Louis Coach Co., but by 1938 renamed Belleville-St. Louis Coach Co., after discontinuing a route which had extended east to Centralia. Belleville-St. Louis Coach Co. tried to expand again in 1941 by acquiring a route from St. Louis to Sparta and Du Quoin from St. Clair Bus Line Co. But by 1945 only intercity segment was from St. Louis to Sparta, and that segment was sold in 1949 to Dixie Greyhound Lines. After then, focused on local service in Belleville, along with route into St. Louis, and route to Scott Air Force Base which was acquired in 1941. Scott Air Force Base route was begun during 1920's by Belleville-Scott Field Motor Bus Co., and from 1924 to 1931 was operated by Superior Motor Bus Co.
Brown Motor Lines - operated between Alton and St. Louis, replacing Illinois Terminal Railroad Co. service in 1953. Controlled by Citizens Coach Co. (below).
Citizens Coach Co. - began operations in 1936, operating local service in Alton.
Community Coach Co. - operated between Granite City and St. Louis, replacing Illinois Terminal Railroad Co. service in 1958.
East St. Louis City Lines - operated local service in East St. Louis, owned by National City Lines.
St. Louis Red Bud & Chester Bus Co. - began operations in 1924 with route from Waterloo to Chester, initially connecting with East St. Louis Columbia & Waterloo Railway Co. interurban line. Service extended from Red Bud to Belleville in 1926. Route extended north into St. Louis after interurban railway was discontinued in 1932. In 1940 replaced by Gulf Transport.
Vandalia Bus Lines - began operations in 1932, acquiring route between St. Louis and Vandalia from Blue Goose Motor Coach. Blue Goose Motor Coach had replaced the interurban railway service between St. Louis and Collinsville in 1928, and in 1930 acquired Red Line Motor Co., which during the 1920's had introduced bus service between Collinsville and Vandalia. Eventually operated local bus service in Collinsville. After takeover of metropolitan service by Bi-State, continued to operate intercity service from St. Louis to Effingham at least into the 1970's. Vandalia Bus Lines continues to exist as charter operator, including contract operation of an Amtrak "Thruway" van between St. Louis and Carbondale.
Baltz Motor Bus Co. - during 1930's operated routes from Belleville to Mascoutah (acquired in 1931 from Superior Motor Bus Co.), and to Millstadt.
Belleville Suburban Bus Lines - as of 1952, provided suburban service.
Caseyville Bus Line - began operations in 1942 with route from Caseyville through Collinsville to East St. Louis, and also with routes to Washington Park and Hollywood Heights. By 1952 also serving Belleville.
Community Motor Bus Co. - began operations in 1924 between Belleville and Nashville, route coexisted with Superior Motor Bus Co.
Davis Transportation Co. - as of 1952, served Collinsville and Edwardsville.
Greenville Bus Co. - from 1943 to 1946, operated between Greenville and the Western Cartridge Co. ammunition plant in East Alton.
Hardin Bus Line - as of 1952, served Pearl, Kampsville, Hardin, Jerseyville, Alton, East Alton.
Hillsboro Transit Co. - as of 1952, served Hillsboro, Edwardsville, vicinities.
Industrial Bus Lines - began operations in 1943, transporting defense workers between Lebanon and East St. Louis.
Lone Star Bunker Hill Bus Co. - began operations in 1942 from Gillespie via Bunker Hill to East Alton. In 1946 acquired Benld Cities Service Bus Co., with routes into East Alton from Litchfield, and from Sawyerville via Benld and Wilsonville.
Millstadt Line Bus Co. - from 1946 to 1949, operated between East St. Louis and Millstadt via Cahokia and Columbia, and from Millstadt to Belleville. During 1930's, service from Millstadt to Belleville had been operated by Superior Motor Bus Co., and later Baltz Motor Bus Co. In 1949, that route was sold to Belleville-Red Bud Coach Co.
Nameoki Transit Co. - began operations in 1942 between Nameoki and Pontoon Beach and Granite City.
O'Fallon-Belleville Coach Co. - began operations in 1940 between its namesake cities, in 1941 extended service to Scott Air Force Base and Mascoutah. From 1941 to 1942 also operated route from Belleville to Carlyle, acquired from Belleville-St. Louis Coach Co. In 1949, that route was sold to Belleville-Red Bud Coach Co.
St. Clair Bus Line Co. - began operations in 1926 between East St. Louis and Sparta.
St. Clair Transit Lines - as of 1952, served East St. Louis, Alorton, Monsanto, Maplewood, Cahokia, Centerville, Pearl Harbor.
Staunton-Livingston Motor Transportation Co. - from 1920 to 1930, operated between its namesake cities.
Superior Motor Bus Co. - between 1920 and 1931, operated routes from Belleville to O'Fallon, Mascoutah and Nashville (introduced 1923 and extended in 1926), Scott Air Force Base (acquired from Belleville-Scott Field Motor Bus Co. in 1924). In 1931, route from Belleville to Mascoutah was sold to Baltz Motor Bus Co.
Wood River & Alton Bus Lines - began operations in 1920, served Alton, East Alton, Wood River, Roxana, Edwardsville, Cottage Hills, Rosewood Heights, Bethalto.