The trucking industry provides the majority of transportation services in the United States. Truck drivers, particularly their driving performance, which influences how customers perceive motor carriers, are integral to the success of their firms. Hence, driver management is a topic of great interest to the trucking industry, logistics practitioners, and logistics researchers. Although the logistics literature does address issues relating to driver management, advice is scarce regarding how motor carriers might manage drivers to improve operational performance and thus the bottom line. Our results shed light on the processes whereby some formal controls directly influence operational performance, whereas others indirectly influence operational performance; that is, in the latter case, the influence of formal controls on operational performance is mediated by certain informal controls. According to our findings, motor carrier firms that employ a combination of formal and informal controls perform better operationally than firms that do not do so. And, thus, those employing such a combination of controls will realize a larger market share.