List of Interstate Highways in Oregon

Interstate Highways of the Oregon Highway System

Interstate 84 markerInterstate 205 marker

Highway markers for Interstate 84 and Interstate 205
System information
Maintained by ODOT
Formed: June 29, 1956[1]
Highway names
Interstates: Interstate nn (I‑nn)
System links

The Interstate Highways in Oregon are the segments of the national Dwight D. Eisenhower System of Interstate and Defense Highways[2] that are owned and maintained by the U.S. state of Oregon. On a national level, the standards and numbering for the system are handled by the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO), while the highways in Oregon are maintained by the Oregon Department of Transportation (ODOT).

These highways are built to Interstate Highway standards,[3] meaning they are all freeways with minimum requirements for full control of access, design speeds of 50 to 70 miles per hour (80 to 113 km/h) depending on type of terrain, a minimum of two travel lanes in each direction, and specific widths of lanes or shoulders;[4] exceptions from these standards have to be approved by the FHWA.[5] The numbering scheme used to designate the Interstates was developed by AASHTO, an organization composed of the various state departments of transportation in the United States.[6]

Primary Interstate Highways

Number Length (mi)[7] Length (km) Southern or western terminus Northern or eastern terminus Formed Removed Notes
I-5 308.14495.90 I5 at the California state lineI5 at the Washington state line 1957current
I-80N 375.17603.78 I-5 / US 30 in PortlandI80N at the Idaho state line 19571980 Renumbered to I-84
I-82 11.0117.72 I82 at the Washington state lineI-84 / US 30 in Umatilla County 1957current
I-84 375.17603.78 I-5 / US 30 in PortlandI84 at the Idaho state line 1980current
  •       Former

Auxiliary Interstate Highways

Number Length (mi)[8] Length (km) Southern or western terminus Northern or eastern terminus Formed Removed
I-105 3.495.62 OR 99 / OR 126 / OR 126 Bus. in EugeneI-5 / OR 126 in Springfield c.1957current
I-205 26.0741.96 I-5 in TualatinI205 at the Washington state line c.1975current
I-305 00 SalemI-5 in Salem proposed
I-405 3.535.68 I-5 in PortlandI5 / US 30 in Portland c.1969current
I-505 00 US 30 in PortlandI-405 / US 30 in Portland proposed
  •       Future

References

  1. McNichol (2006), p. 106.
  2. Swift, Earl (2011). The Big Roads: The Untold Story of the Engineers, Visionaries, and Trailblazers Who Created the American Superhighways. Boston: Mariner. p. 5. ISBN 978-0-547-90724-6.
  3. Lewis, Tom (2013). Divided Highways: Building the Interstate Highways, Transforming American Life (Updated ed.). Ithaca, NY: Cornell University Press. p. 253. ISBN 978-0-8014-7822-2.
  4. McNichol (2006), pp. 10–11.
  5. Zander, Mark, ed. (September 19, 2013). "Chapter 11: Design, Section 44: Interstate Highways" (PDF). Facilities Development Manual. Wisconsin Department of Transportation. p. 2. Retrieved April 14, 2014.
  6. McNichol (2006), pp. 57, 121.
  7. Staff (October 31, 2002). "Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of October 31, 2002". Route Log and Finder List. Federal Highway Administration. Retrieved January 2014.
  8. Staff (October 31, 2002). "Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of October 31, 2002". Route Log and Finder List. Federal Highway Administration. Retrieved January 2014.