Evaluating Impacts to Freight Logistics from Highway Improvements Using Reliability Metrics

Unreliable transportation networks cause catastrophic failures in modern freight logistics. Scheduled logistics must consider the differences in traffic patterns that occur across the temporal and spatial domains of freight networks. Recent advancements in data collection (e.g., probe vehicle data) enable planners to assess discrete time periods of scheduled operations to measure changes in the reliability of transportation networks. Instinctively, infrastructure projects that improve system capacity will also benefit truck travel time reliability (TTTR); however, there is a need to develop methods that assess the influence of variations in freight-specific operating conditions. In this paper, we investigate several years of data to monitor the performance of a system that is subject to disruptions from infrastructure and environmental changes. Specifically, the TTTR performance is monitored before, during, and after capacity improvements have been constructed for a highway transportation project. The methods introduced with this paper demonstrate that a freight reliability metric has a unique response to capacity modifications that may not be otherwise discernable when measuring performance changes with traditional metrics. This approach describes how infrastructure improvements will influence freight transport reliability.