Road Congestion is being defined asĀ a road having a volume-to-capacity ratio over 1.0. This means that the traffic on the road is more than the road’s intended capacity. Reliability refers to the predictability and dependability of travel times on transportation infrastructure. Improvements in reliability may be highly valued by transportation system users, particularly for freight movement. Improved reliability of travel time creates additional value. This reflects the fact that uncertainty makes travelers and freight operators adjust their departure times to account for the possibility that their trips may take longer than usual. The less uncertain they are about the extra time they need to allocate for this contingency, the more precisely they can schedule their trip, which saves them time.