Comment from Timothy Benedict

This comment is directed towards #5 under data gaps, specifically Freight Analysis Framework (FAF) data. I’m attaching a paper that provides additional detail and mitigation options. Apparently, modal assignment for foreign trade is an imputed field rather than a directly observed one, and FAF cannot distinguish, for an import's inland leg, between a marine container drayed intact to its final destination, freight transloaded into a domestic 53-foot dry van for over-the-road truck movement, and freight transloaded into a domestic 53-foot intermodal container for rail movement. All three are coded identically in FAF's domestic-mode field. Three 40-foot standard ocean containers can be transloaded into two 53-foot dry vans, a common practice among retail importers. This measurement gap is operationally significant because transloading is one of the largest factors of inland routing economics at major U.S. container ports. Approximately 30% of all containers handled at North American West Coast ports are transloaded into domestic containers for inland rail movement, according to Notteboom, Pallis, and Rodrigue (2022). The same operational logic that makes transloading rational for shippers and ocean carriers – short equipment cycles, heavy loading, distribution flexibility, detention and demurrage exposure – is what makes it statistically invisible to FAF. As a result, port-adjacent FAF zones systematically over-report domestic outbound truckload flows, and academic and policy analyses built on FAF data carry an undocumented data quality limitation that affects emissions modeling, port competitiveness analysis, infrastructure planning, and modal diversion studies.