How far does your food travel on the highway? Food miles and carbon footprint

Abstract

As concerns over the environmental impacts of food transportation grow, the concepts of food miles and their associated carbon footprint have gained increasing attention. This study proposes a novel food assignment model designed to more accurately estimate food miles and related CO2 emissions. Drawing inspiration from the traffic assignment problem, the model simulates the distribution of food flows across a transportation network. Using county-level production–consumption matrices for four food categories—aquaculture, livestock, crops, and dairy—across Texas, we estimate both food miles and carbon emissions. The results indicate a total annual food miles of 2,719,898 kt-km and CO2 emissions of 274 kt. Among road types, livestock transport along U.S. highways accounted for the largest share, with 1,548,926 kt-km and 126 kt of CO2 emissions annually. Regionally, northern Texas recorded the highest emissions at 106 kt per year. The analysis also reveals that most food is produced in northern Texas and transported to the western and southeastern regions. To assess the model’s validity, its estimates were compared to those from conventional food mile calculation methods, showing approximately 5.7% higher results. The proposed approach offers a robust foundation for evaluating and planning sustainable food transportation systems through improved accuracy in food mile assessment.