The purpose of this article is to develop a model for managing duplicates at a motor transport if there is an insurance reserve. The task is to minimize the total costs (losses) at the motor transport enterprise. For an optimal model of duplicates management, regardless of the supplier and the time of delivery, the insurance stock in the warehouses of motor transport enterprises will satisfy the demand for spare parts necessary for rolling stock. Also, taking into account the determination of the optimal size of duplicates, the prediction of sudden failures, as well as statistics maintained in the Procurement service of motor transport enterprises, the volume and frequency of orders for duplicates become known. Determining the size of duplicates batch of various classification and quality allows the MTS (material and technical support) services of motor transport enterprises to ensure not only an uninterrupted transport process, but increase the coefficient of technical readiness and save on previously unclaimed stocks (surpluses) ensuring the effective distribution of financial resources. Further research in this area will be aimed at determining duplicates quality, supplied to the motor transport enterprise and developing methods for assessing the risk of the impact of defects in spare parts on failures and further consequences.