Freight transportation is essential to maintaining commerce and economies in the United States and globally. However, freight transportation is known to have significant environmental and public health impacts. Harmful emissions of carbon dioxide, methane, hydrofluorocarbons, and black carbon increase the risk of global climate change. Emissions of nitrogen oxides and particulate matter contribute to serious public health risks including increased incidences of premature death, and increased severity of respiratory and cardiovascular illness. As trade is increasingly globalized and economies expand, harmful air emissions from goods movement are projected to increase at faster rates than all other sources of transport-related emissions. While mandatory rules such as advanced vehicle emission and fuel quality standards reduce emissions from new vehicles, the vast legacy fleet of heavy duty diesel vehicles present a challenge for policy makers around the world. This paper examines how a voluntary policy model, the U.S. Environmental Protection Agency's SmartWay Transport Partnership, fosters behavior change, facilitates strategic interactions and enables more informed decision-making in the freight sector to improve performance and reduce emissions. The effectiveness of this innovative model has generated international interest and led to program replication in other countries.