Improving Statewide Freight Routing Capabilities for Sub-National Commodity Flows

The ability to fully understand and accurately characterize freight vehicle route choices is important in helping to inform regional and state decisions. This project recommends improvements to WSDOT’s Statewide Freight GIS Network Model to more accurately characterize freight vehicle route choice. This capability, when combined with regional and sub-national commodity flow data, will be a key attribute of an effective statewide freight modeling system. To come to these recommendations, the report describes project activities undertaken, and their outcomes, including 1) a review of commercially available routing software, 2) an evaluation of the use of statewide GPS data as an input for routing analysis, and 3) the design, implementation, and evaluation of a survey of shippers, carriers, and freight forwarders within the state. The software review found that routing software assumes least cost paths while meeting user specified constraints, and it identified criteria for evaluation in the subsequent survey. The GPS data evaluation showed that significant temporal shifting occurs rather than spatial route shifting, and it revealed significant limitations in the use of GPS data for evaluating routing choices, largely because of the read rate. Among the survey results was that the first priority of shippers, carriers, and freight forwarders is to not only meet customer requirements, but to do so in the most cost-efficient way. From a latent class analysis of routing priorities, we discovered that distance-based classification best clusters similar routing behavior. The report includes recommendations for implementing this within the Statewide Freight GIS Network Model.