Transportation justice is a multidisciplinary academic concept and field of research that critically examines the equitable distribution of transportation benefits and burdens, and the fairness of processes governing transportation planning, provision, and outcomes. It investigates how transportation systems create or exacerbate social inequalities by influencing access to opportunities, mobility, environmental impacts, and economic costs, with a particular focus on the experiences and needs of marginalized and vulnerable populations. Its significance lies in informing policy, practice, and advocacy aimed at achieving more just and equitable transportation systems.