LIMSwiki
| Interstate Highways of the Oregon Highway System | |
|---|---|
   Highway markers for Interstates in Oregon | |
 Interstate Highways highlighted in red | |
| System information | |
| Maintained by ODOT | |
| Formed | June 29, 1956[1] |
| Highway names | |
| Interstates | Interstate nn (I-nn) |
| US Highways | U.S. Route nn (US nn) |
| State | Oregon Route nn (OR nn) |
| Named highways | xx Highway No. 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 115 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]
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 (forerunner to the AASHTO).[7] The last section of the Interstate Highway system to be built in Oregon, on I-82 near Hermiston, opened on September 20, 1988.[8]
Primary Interstate Highways
| Number | Length (mi)[9] | 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 | ||
| ||||||||
Auxiliary Interstate Highways
| Number | Length (mi)[10] | 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 | 1958 | current | ||
 I-305
|
— | — | Salem | I-5 in Salem | c. 1957 | 1967 | ||
 I-405
|
3.53 | 5.68 | I-5 in Portland | I-5 / US 30 in Portland | 1958 | current | ||
 I-505
|
— | — | US 30 in Portland | I-405 / US 30 in Portland | c. 1957 | 1988 | ||
| ||||||||
References
- McNichol, Dan (2006). The Roads that Built America. New York: Sterling. ISBN 1-4027-3468-9.
- Kramer, George. "Interstate 50th Anniversary: The Story of Oregon's Interstates" (PDF). Compiled by Oregon Department of Transportation. Oregon Department of Transportation. Archived from the original (PDF) on December 15, 2006. Retrieved August 31, 2016.
- Staff (May 2004). "The Interstate Highway System in Oregon: A Historic Overview" (PDF). Oregon Department of Transportation.[permanent dead link]
- ^ McNichol (2006), p. 106.
- ^ 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.
- ^ 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.
- ^ McNichol (2006), pp. 10–11.
- ^ Zander, Mark, ed. (September 19, 2013). "Chapter 11: Design, Section 44: Interstate Highways" (PDF). Facilities Development Manual. Wisconsin Department of Transportation. p. 2. Archived from the original (PDF) on April 16, 2014. Retrieved April 14, 2014.
- ^ McNichol (2006), pp. 57, 121.
- ^ "Correspondence, A. E. Johnson and W. C. Williams". American Association of State Highway Officials. May 15, 1958. pp. 1–2. Retrieved April 2, 2021 – via AASHTO Route Numbering Archive.
- ^ Cockle, Dick (September 21, 1988). "Final segment completes freeway system". The Oregonian. p. B4.
- ^ Adderly, Kevin (January 27, 2016). "Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of December 31, 2015". Route Log and Finder List. Federal Highway Administration. Retrieved August 31, 2016.
- ^ Adderly, Kevin (January 27, 2016). "Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of December 31, 2015". Route Log and Finder List. Federal Highway Administration. Retrieved August 31, 2016.
External links
Media related to Interstate Highways in Oregon at Wikimedia Commons- Oregon Department of Transportation website
- Oregon highways at AARoads.com
