Traffic matrices (TM) are commonly used in classical networks to optimize routing and improve overall network performance. These matrices give essential information about the current state of the network and serve as a key tool for efficient and optimal traffic distribution. However, their applicability in quantum networks has not yet been explored. In this paper, we first introduce the concept of TM in quantum networks, called quantum traffic matrices (QTM). Furthermore, we introduce two parameters: QTM based link cost function and QTM based network cost. We then analyze the network cost associated with using QTM for entanglement routing, with the goal of gaining deeper insight into their practical value and effectiveness. Our simulation results indicate that as the size of the network increases, the cost of using these matrices increases. Furthermore, we analyze the cost of the network in relation to the utilization ratio of entanglement (EUR). The result shows that when the EUR is low, the network cost increases, whereas higher EUR values lead to a reduction in network cost. In addition to this, we investigate the cost of the network in relation to the average fidelity. The results indicate a significant decrease in network cost as fidelity increases. Lastly, we analyze the cost of the network in relation to the entanglement distribution rate (EDR). The results show that when the EDR is low, the network cost increases, whereas higher EDR values lead to a reduction in cost. These results highlight the need for techniques that reduce the complexity of QTM construction and reduce storage overhead to enable scalable and efficient entanglement distribution in quantum networks.