The Association of American Railroads (AAR) is an industry trade group representing the freight railroads of North America (Canada, Mexico and the United States). Amtrak and some regional commuter railroads are also members.

AAR was created in 1934 by the merger of five industry-related groups:

• the American Railway Association,
• the Association of Railway Executives,
• the Bureau of Railroad Economics,
• the Railway Accounting Officers Association, and
• the Railway Treasury Officers Association.

One of the AAR's duties is to oversee the assignment of reporting marks – two to four letter codes that uniquely identify the owner of any piece of railroad rolling stock or intermodal equipment (trailers, containers, etc.) that can be carried on a railroad. The AAR also classifies railroads into Class I, Class II and Class III based on income.

See also

• List of AAR reporting marks

External links

• Association of American Railroads website