Interstate 505 (I-505) is a north–south Interstate Highway in the Sacramento Valley in Northern California. It is a spur auxiliary route of I-5 that runs from near Dunnigan south to I-80 in Vacaville. I-505 is primarily a rural Interstate, but travels through Vacaville and the city of Winters. The highway is the primary route connecting the San Francisco Bay Area and the northern Sacramento Valley, bypassing Sacramento and its attendant city traffic. Thus, it is a major route for travelers heading directly from the San Francisco Bay Area to the Pacific Northwest.
I-505 highlighted in red
|Auxiliary route of I-5|
|Defined by Streets and Highways Code § 617|
|Maintained by Caltrans|
|Length||32.99 mi (53.09 km)|
|South end||I-80 in Vacaville|
|North end||I-5 near Dunnigan|
The southern terminus of I-505 is at I-80 next to the Nut Tree Airport in the Nut Tree area in Vacaville. From there, it travels north about ten miles through rural areas near the western edge of the Sacramento Valley before reaching Winters. I-505 then skirts the eastern city limits of Winters, intersecting with State Route 128 – the only exit in Winters. After leaving that city, the interstate then proceeds north through rural areas again for about 20 miles until it reaches its northern terminus with I-5 near Dunnigan.
For most of its length, I-505 is a four-lane freeway, which is typical for rural interstates in California.
I-505 is part of the California Freeway and Expressway System, and is part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration.
What is now I-505 was originally conceived as part of a loop Interstate with a directional suffix, I-5W. However, I-5W and most of the other Interstates around the country with directional suffixes were eventually renumbered or eliminated, except I-35E and I-35W in Texas and Minnesota and I-69 segments I-69W, I-69C and I-69E in southern Texas. The former route of I-5W now corresponds to I-580 from I-5 south of Tracy to Oakland, I-80 from Oakland to Vacaville, and I-505 from Vacaville to I-5 near Dunnigan.
|Solano||Vacaville||0.00||0.00||1||I-80 – San Francisco, Sacramento||Southern terminus; southbound exit and northbound entrance; signed as exit 1A (west) and 1B (east); I-80 exit 56|
|0.00||0.00||Orange Drive / Nut Tree Road||Northbound exit (from I-80 east) and entrance|
|0.00||0.00||1B||Monte Vista Avenue||Southbound exit and entrance (to I-80 east)|
|1.45||2.33||1C||Vaca Valley Parkway||Signed as exit 1 northbound|
|||10.43||16.79||10||Putah Creek Road|
|Yolo||||11.03||17.75||11||SR 128 west / CR E6 east – Winters, Davis||Eastern terminus of SR 128; western terminus of CR E6|
|||21.25||34.20||21||SR 16 – Woodland, Esparto|
|||28.08||45.19||28||CR E10 (Road 14) – Zamora|
|||32.99||53.09||I-5 north – Redding||Northern terminus; northbound exit and southbound entrance; I-5 south exit 553|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
- California Department of Transportation (October 2014). "Log of Bridges on State Highways". Sacramento: California Department of Transportation.
- "Article 2 of Chapter 2 of Division 1 of the California Streets and Highways Code". Sacramento: California Office of Legislative Counsel. Retrieved February 6, 2019.
- Federal Highway Administration (March 25, 2015). National Highway System: California (North) (PDF) (Map). Scale not given. Washington, DC: Federal Highway Administration. Retrieved July 29, 2017.
- Natzke, Stefan; Neathery, Mike & Adderly, Kevin (June 20, 2012). "What is the National Highway System?". National Highway System. Washington, DC: Federal Highway Administration. Retrieved July 1, 2012.
- "California Highways-Routes 1-8". California Highways. Retrieved September 3, 2012.
- California Department of Transportation, California Numbered Exit Uniform System, Interstate 505 Freeway Interchanges, Retrieved on 2009-02-07.