In 1927 the bus subsidiary Western Motor Coach Co. began providing bus service supplementing the interurban railway lines. In addition to a route paralleling the railroad between Chicago and Geneva primarily via Roosevelt Rd., Western Motor Coach Co. introduced more direct bus routes from Chicago to Aurora primarily via Ogden Ave., and from Chicago to Elgin primarily via Lake St. And Western Motor Coach Co. became the operator of the Mount Carmel bus service.
Also in 1927, a route was introduced between Elmhurst and Hinsdale. And in 1928, an agreement was approved with Northern Illinois Service Corp., which had operated from Geneva as far west as the Mississippi River. This enabled through service from Chicago west. Northern Illinois Service Corp. soon after became Pickwick Greyhound Lines of Illinois.
In 1930, Western Motor Coach Co. was combined into Metropolitan Coach Co., the bus subsidiary of the Chicago North Shore and Milwaukee Railroad, also controlled by Samuel Insull. In that year, Metropolitan Coach Co. introduced two feeder bus routes in Elmhurst, operating north of the Chicago Aurora and Elgin station. But the routes were unsuccessful, and were discontinued in 1931.
In 1930, the Chicago-Aurora route was sold to Cannon Ball Motor Transportation Co., which in 1935 became part of Burlington Transportation Co., later Burlington Trailways. In 1955, this route was sold to Bluebird Coach Lines, which in 1965 became West Suburban Transit Lines, which never did operate route.
And in 1931, the route between Chicago and Elgin was sold to Northland Greyhound Lines, part of the Greyhound system. And in 1932, the Chicago-Geneva route was sold to Interstate Transit Lines, which later became part of Overland Greyhound Lines, also part of the Greyhound system.
By 1933, the Mount Carmel service and the Elmhurst-Hinsdale routes were discontinued. The Chicago Aurora and Elgin Railroad became an operator of buses again in 1937, when buses replaced trains on the branch to Geneva and St. Charles. Service was extended south of Geneva to Batavia in 1953, when rail service on the Batavia branch was reduced to rush hours only. Service was abandoned, along with the rail passenger service, in 1957.