In the 1940s, Mattoon became a hub for the oil industry as companies large and small opened offices there, drawn by developing oil fields, the business environment, and quality of life. Several oil companies had begun leasing land southwest of Mattoon as early as 1936, a wildcat venture in 1939 fueled speculation, a small field opened in 1940, and by 1946 there were 415 active wells, with more than half still pumping ten years later. The oil business brought new people, ideas, and technical vocabulary tied to geologic formations such as Devonian, McClosky, and Aux Vas. At the same time, development of diesel engines made trains more efficient and economical but reduced the need for railway shops that had been central to Mattoon's economy, and shop closings in 1953 brought significant job losses as that era ended. After the war, Young Radiator purchased the Atlas Diesel factory and produced oil field equipment and heavy duty radiators throughout the 1950s, while prominent manufacturers such as General Electric, Kal Kan, and R.R. Donnelley arrived in later decades. Postwar transportation also changed as the Checker Top Cab Company, started by Albert J. Hunt in the mid-1940s, grew to a fleet of 12 cabs at its peak; airport buildings constructed in 1942 served private aviation until 1951 before the Coles County Airport was built; Illinois Route 16 between Mattoon and Charleston was constructed in the late 1950s; Interstate 57 opened in Mattoon in 1966; roads first paved in the 1920s were largely repaved in the 1950s; and cruising became a popular pastime, with Gill's Drive Inn, opened by Harold and Grace Gill in 1949, serving as a headquarters for mobile teens. As production shifted from war goods to consumer goods, car culture came of age and the road replaced rail as the dominant way to move people and goods.