List of Interstate Highways in Oregon

Interstate Highways of the Oregon Highway System
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
Oregon Highways Interstate US State Named Scenic

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	308.14	495.90	I‑5 at the California state line	I‑5 at the Washington state line	1957	current
I-80N	375.17	603.78	I-5 / US 30 in Portland	I-80N at the Idaho state line	1957	1980	Renumbered to I-84
I-82	11.01	17.72	I‑82 at the Washington state line	I-84 / US 30 in Umatilla County	1957	current
I-84	375.17	603.78	I-5 / US 30 in Portland	I-84 at the Idaho state line	1980	current
Former

Auxiliary Interstate Highways

Number	Length (mi)[8]	Length (km)	Southern or western terminus	Northern or eastern terminus	Formed	Removed
I-105	3.49	5.62	OR 99 / OR 126 / OR 126 Bus. in Eugene	I-5 / OR 126 in Springfield	c. 1957	current
I-205	26.07	41.96	I-5 in Tualatin	I‑205 at the Washington state line	c. 1975	current
I-305	—	—	Salem	I-5 in Salem	1950	1960
I-405	3.53	5.68	I-5 in Portland	I‑5 / US 30 in Portland	c. 1969	current
I-505	—	—	US 30 in Portland	I-405 / US 30 in Portland	1950	1970
Future

References

• McNichol, Dan (2006). The Roads that Built America. New York: Sterling. ISBN 1-4027-3468-9.
• Staff. "Interstate 50th Anniversary: The Story of Oregon’s Interstates" (PDF). Oregon Department of Transportation. Retrieved September 2007.
• Staff (May 2004). "The Interstate Highway System in Oregon: A Historic Overview" (PDF). Oregon Department of Transportation.

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.