The U.S. agricultural and food supply chains are essential not just for local but also for global food security. The U.S. government actively leads both local and global food security initiatives that aim to provide stable, affordable, and accessible food supplies. Multi-modal and large-scale transportation infrastructure is crucial to the continuous agri-food movement from producers to final consumers. Yet, a comprehensive understanding of how these transportation infrastructures support agri-food transit nationwide is needed. High-resolution and real-world information on agri-food movement on highways, railways, and waterways can guide policy on infrastructure investments for food security.
In our new study in Nature Food, we map the birds-eye view information on agri-food movement onto the real-world routes along the U.S. highways, railways, and waterways. We extend our mapping technique for individual agri-food commodity groups (SCTG 01-07) and flow types (domestic, import, export). Through such study, we identify which U.S. region and transportation mode combination is more heavily utilized for domestically consumed, imported, and exported food commodities (Figure 1). We also quantify how each transportation mode balances cost, resilience, and sustainability for agri-food commodities.
As seen in Figure 2, we find that highways along the U.S.-Mexico and U.S.-Canada borders are where majority of the agri-food transit takes place for imported goods. Also, highways that connect the nation to the Port of New Orleans carry significant amounts of agri-food that is to be exported abroad through barges. For waterways, imports seem to arrive to the ports in California whereas domestically produced and consumed goods almost solely move along the Mississippi River. For distributing agri-food commodities between their domestic origin and destinations, railways that connect East Coast to West Coast are very valuable as well as the railroads along the U.S.-Mexico border for imports and railroads along the U.S.-Canada borders for exports. In addition to Mississippi river transit, highways accumulated around the Midwest also carries major agri-food mass for domestic consumption.
Lastly, we quantify how each transportation mode balances transit cost, emission, and adaptability (Figure 3). We find that highways are the most adaptable choice of transit as they have multiple alternative routes that carry even agri-food loads between U.S. regions. This means that, in case of disruptions along one of the highway routes, transit can still continue with minimal imbalance between supply and demand. However, highways emit the highest carbon dioxide per ton-mile transit and accumulate the highest cost. On the contrary, waterways have the lowest carbon emissions and are the most affordable form of agri-food transit. Yet, due to natural constraints, there are very few alternate pathways – Mississippi River carries almost all the agri-food load and in case of climate change induced water height decreases or port/dam closures, there is no chance of re-routing the load along the river. Meanwhile, railways provide intermediate values for transit cost, adaptability, and emission which highlights their potential to be restored, strengthened, and expanded for agri-food transit going forward.
Our analysis shows the potential value of mapping agri-food, essential goods for the nation’s economic and social well-being, movements along the real-world transportation routes in order to guide future policy and decision-making regarding food security and infrastructure investments. Our findings can help to pinpoint where and for which transportation mode modernization, expansion, and restoration activities could be scheduled. Further, by providing a tradeoff analysis across resilience, efficiency, and sustainability, we also illustrate the need to consider balancing multiple goals for agri-food transit.