Mr. Roberts worked full time at a Lear Siegler plant in Grand Rapids while attending WMU. In 1977, he became a salaried-employee-in-training for General Motors and rose to various positions of greater responsibility.
He was elected corporate vice president in charge of personnel administration and development in 1987. Three years later, he was named manufacturing manager for the Cadillac Motor Car Division.
In 1992, he was appointed vice president and general manager of the GMC Truck Division.