In the '60s, Bill Swisher, founder and chairman of CMI Corporation, introduced the first automatically controlled fine-grade trimmer that permitted high-production, highly accurate final grade preparation. The machine, introduced in 1964, was called the Auto-Grade. A series of automated placing and slipform concrete paving machines were developed from this starting point, and within three years, these machines had gained international acceptance. They remain one of the principal means of modern expressway, highway, and airport runway construction.
Swisher's later innovations included the first dedicated pavement milling machine used in road rehabilitation, introduced in 1975. With more than 50 patents to his credit, many of Swisher's innovations were the forerunners of paving equipment in use today.