Valuing travel time reliability is an important element of travel choice modeling. In this paper, we introduce the notion of variation cost in the utility function, capturing the variations in both queuing cost and scheduling cost endogenously under degradable capacity, and develop a theoretical framework to derive the departure choice. We then define the value of capacity reliability to be the marginal influence of capacity degradation on the overall system generalized cost. Through this framework, a single-step tolling scheme is proposed to reduce the queuing cost and cost variability. The study illustrates the combined impact of cost variability, capacity degradation, and how road pricing will impact on travelers' departure profile and the overall system generalized cost.