For the need a of realtime decisionmaking in safety management of road network operation, models based on Bayesian analysis (BA) for calculation of reliability of road traffic system were presented. Based on road traffic system models constructed with theories in system engineering, the concept of reliability of road traffic system was defined with reliability engineering, and reliability models of four kinds of road traffic systems were constructed respectively. To solve problems in application of the reliability models, Bayesian network (BN) was introduced to construct BNcoupled reliability models for road traffic systems. A case study was conducted to illustrate the use of the BNcoupled models.