This study develops uniform techniques for accurately estimating the incremental change in overall system cost due to planned, small scale bus service changes. Current costing procedures were catalogued and evaluated. Based on investigation of factors that influence costs, a proposed technique was devised. Its strengths and weaknesses were appraised relative to other known methods. Chapter 2 reviews costing procedures that have been applied in the past. Chapter 3 presents an overview of the proposed method which concentrates on driver wages and benefits and those provisions of work rules which affect computation of total compensation. Both the calibration and application phases are described in a step-by-step manner. Chapter 4 describes the testing program for the proposed method. For comparison, baseline costs were established using a scheduling-based, cost bulid-up approach. Other costing methods were also tested. Using Twin Cities Transit as a test site, approximately a dozen service changes were costed. Chapter 5 summarizes the overall capability and performance of the proposed method. Proposals are also made for further research in those areas offering the most promise. Automation is seen as simplifying resource requirements for applying the costing method.