The Freight Data Users Forum is an annual event that brings together the expert community of freight data users to share experience, learn about recent advances, and provide input on next generation needs related to a critical and timely freight data product or process. This year's freight data forum will discuss Freight Performance Measures required by MAP-21 and the FAST Act. Individuals from FHWA and several state DOTs will discuss their recent work investigating factors that influence freight network performance and linking travel time data with broader freight system policy objectives. States, MPOs, and other stakeholders interested in freight performance measurement are encouraged to attend - this event is open to all TRB attendees.
Overview of National Freight Performance Measure Efforts
Jeffrey Purdy, Federal Highway Administration (FHWA)View Presentation
Modeling Interstate Truck Reliability of Several Southeastern States of the United States
Chowdhury Siddiqui, South Carolina Department of TransportationShow Abstract
With the national performance management measure rulemaking assessing the reliability of the freight movement on the Interstate system has become a mandatory task for the State Departments of Transportation. This includes yearly reporting of the performance measures and setting targets for them for future years. This paper proposes a methodology to assess the association of the truck travel time reliability (TTTR) with various traffic and roadway-related attributes. TTTR is a critical part in the freight reliability metric. States are required to asses it for five different time periods. The paper presents two Generalized Linear Models (GLMs) to assess the significant predictors associated with the maximum TTTR among these five time periods. The results show that the GLM with log-link function has a modest superiority over the GLM with identity-link function in terms of R-squared fit and standard errors of the coefficient estimates of the predictors. The results from the models revealed that the directional traffic volume and urban areas were positively associated with the maximum TTTR. Whereas, length of the TMC, number of lanes and percent of combination trucks were among the common attributes negatively influencing the TTTR. In addition to the combined models of the entire study region, State-specific models were developed to better understand the variability of the direction and magnitude of the associativity of the predictors. Understanding these relationships can help States not only to prudently set future years’ target but also to identify the attributes that could potentially contribute to a higher truck reliability index.
Linking Land Use and Freight Performance Measurement: Lessons from New York State
Catherine Lawson, SUNY AlbanyView Presentation