The American Association of State Highway and Transportation Officials or by its acronym in English AASHTO*,* of American Association of State Highway and Transportation Officials, is a body that establishes standards, publishes specifications and tests protocols and guides used in the design and construction of highways throughout the United States. Despite its name, the association represents not only roads, but also air, rail, water and public transportation.

AASHTO is made up of members of the Department of Transportation from each state in the United States, as well as from Puerto Rico and the District of Columbia. The United States Department of Transportation, some American counties and cities, toll operators, most Canadian provinces as well as Hong Kong's highway departments, Turkey's Minister of Works and Settlements, and the Nigerian Association of Highway and Public Transportation Officials are non-voting observer members.

-Some fundamental publications for civil engineering published by AASHTO are:[1]​.

In addition to these publications, AASHTO collaborates on research projects. One of these projects is the AASHO Road Test, which consists of a testing campaign throughout the country to study road surfaces with the aim of designing more resistant and optimal surfaces.

AASHTO also functions as an accreditor of laboratories in the country. In the event that a bridge is built with a certain compressive strength of concrete, the verification laboratory will be required to be accredited by AMRL, the AASHTO materials reference laboratory.