The knowledge of the process of the deterioration of structural resistance is crucial for existing bridge assessment. However, precisely modeling the process of loading also affects the evaluation. Indeed traffic loading is one of the main loads that a bridge is subjected to in its service time. This paper investigates the role of traffic loading on the time-dependent reliability of a given bridge. Emphasis is placed on updating traffic load effect models with consideration of traffic evolution due to traffic growth, change of traffic composition and modification of the weight limit regulation. Moreover, loss of resistance due to chloride induced corrosion is taken in account. Finally, the annual reliability is evaluated to quantify the influence of traffic evolution on the reliability of a reinforced concrete bridge.