A highly automated, real-time dispatch system is described which uses embedded optimization routines to replace extensive manual operations and substantially reduce operating costs for a nation-wide fleet of petroleum tank trucks. The system is currently used in daily operations by the Order Entry and Dispatch segment of the Chevron U.S.A., Inc., Marketing Department. From a central facility, refined petroleum products valued at more than 10 billion dollars per year are dispatched from more than 80 bulk terminals on a fleet exceeding 300 vehicles in approximately 2600 loads per day. Design, implementation and use of the central dispatch routines are discussed from the perspective of transaction modules within a large management information system. This environment presents special challenges for the optimization methods, developed for certified performance on dispatch models specified as integer programs. Objectives include minimizing transportation costs as well as equitable man and equipment workload distribution, safety, customer service, and satisfaction of equipment compatibility restrictions.