Economy in Motion: The National Multimodal and Sustainable Freight Infrastructure Act - Directs the Secretary of Transportation to: (1) establish a Multimodal Freight Funding Formula Program to distribute funds to states, and a National Freight Infrastructure Competitive Grant Program to make grants to entities for projects, to improve the efficiency and reliability of freight movement in the United States; (2) establish a multimodal national freight network to accomplish the goals of the national freight policy, including increasing the productivity and efficiency of the national freight system and improving its safety, security, and resilience; (3) develop, maintain, and post on the public website of the Department of Transportation (DOT) a national freight strategic plan that includes an assessment of the condition and performance of the national freight system; and (4) develop and improve tools to support an outcome-oriented, performance-based approach to evaluate proposed freight-related and other transportation projects.

Amends the Moving Ahead for Progress in the 21st Century Act (or MAP-21) to: (1) expand the membership and duties of state freight advisory committees; and (2) require state freight plans to include strategies and goals to decrease greenhouse gas emissions, local air pollution, water runoff, and wildlife habitat loss.  

Amends the Internal Revenue Code to: (1) impose a 1% excise tax upon taxable ground transportation of property (i.e., transportation by freight rail or transportation by commercial motor vehicle for a distance of more than 50 miles), and (2) deposit such tax revenues into a Freight Trust Fund (established by this Act) to finance the Multimodal Freight Funding Formula Program and the National Freight Infrastructure Competitive Grant Program.