The Interstate Highways in Oregon are the segments of the national Dwight D. Eisenhower System of Interstate and Defense Highways that are owned and maintained by the U.S. state of

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

. On a national level, the standards and numbering for the system are handled by the

Federal Highway Administration The Federal Highway Administration (FHWA) is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two programs, the Federal-aid Highway Program a ...

(FHWA) and the

American Association of State Highway and Transportation Officials The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test quality control, protocols, and guidelines that are used in highway design and construction through ...

(AASHTO), while the highways in Oregon are maintained by the

Oregon Department of Transportation The Oregon Department of Transportation (ODOT) is a department of the state government of the U.S. state of Oregon responsible for systems of transportation. It was first established in 1969. It had been preceded by the Oregon State Highway Depar ...

(ODOT). These highways are built to

Interstate Highway standards Standards for Interstate Highways in the United States are defined by the American Association of State Highway and Transportation Officials (AASHTO) in the publication ''A Policy on Design Standards: Interstate System''. For a certain highway to ...

, meaning they are all

freeway A controlled-access highway is a type of highway that has been designed for high-speed vehicular traffic, with all traffic flow—ingress and egress—regulated. Common English terms are freeway, motorway and expressway. Other similar terms ...

s with minimum requirements for full control of access, design speeds of depending on type of terrain, a minimum of two travel lanes in each direction, and specific widths of lanes or shoulders; exceptions from these standards have to be approved by the FHWA. The

numbering scheme There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key of a database management ...

used to designate the Interstates was developed by AASHTO, an organization composed of the various state departments of transportation in the United States. The Oregon state government initially proposed numbering the auxiliary Interstates using lettered suffixes, but were denied in 1958 by the

American Association of State Highway Officials The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test protocols, and guidelines that are used in highway design and construction throughout the United St ...

(forerunner to the AASHTO). The last section of the Interstate Highway system to be built in Oregon, on

I-82 Interstate 82 (I-82) is an Interstate Highway in the Pacific Northwest region of the United States that travels through parts of Washington and Oregon. It runs from its northwestern terminus at I-90 in Ellensburg, Washington, to its southeaste ...

near Hermiston, opened on September 20, 1988. __TOC__

Primary Interstate Highways

Auxiliary Interstate Highways

References

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External links

*{{commons category inline, Interstate Highways in Oregon
Oregon Department of Transportation websiteOregon highways
at AARoads.com Interstate