View source for Interstate 8

{{Short description|Interstate Highway in California and Arizona}}
{{Other uses|I8 (disambiguation)}}
{{Use American English|date=April 2025}}
{{Use mdy dates|date=May 2023}}
{{featured article}}
{{Infobox road
| country = USA
| type = I
| route = 8
| maint = [[Caltrans]] and [[Arizona Department of Transportation|ADOT]]
| length_mi = 350.34
| length_notes = {{convert|171.98|mi|km}} in California<ref name=calnexus/><br />{{convert|178.36|mi|km}} in Arizona<ref name="ADOT Highway Log"/>
| established = 1964
| map = {{maplink-road|from=Interstate 8.map}}
| map_custom = yes
| map_notes = I-8 highlighted in red
| direction_a = West
| terminus_a = Sunset Cliffs Boulevard&nbsp;/ Nimitz Boulevard in [[San Diego|San Diego, CA]]
| junction = {{Plainlist|<!-- Major junctions only; Only up to ten most major intersections and cities belong here; please read [[WP:USRD/STDS]] for more info -->
*{{Jct|state=CA|I|5}} in San Diego, CA
*{{Jct|state=CA|SR|163}} in San Diego, CA
*{{Jct|state=CA|I|805}} in San Diego, CA
*{{Jct|state=CA|I|15|SR|15}} in San Diego, CA
*{{Jct|state=CA|SR|125}} in [[La Mesa, California|La Mesa, CA]]
*{{Jct|state=CA|SR|67}} in [[El Cajon, California|El Cajon, CA]]
*{{Jct|state=CA|SR|111}} in [[El Centro, California|El Centro, CA]]
*{{Jct|state=AZ|US|95}} in [[Yuma, Arizona|Yuma, AZ]]
*{{Jct|state=AZ|SR|85}} in [[Gila Bend, Arizona|Gila Bend, AZ]]
}}
| direction_b = East
| terminus_b = {{Jct|state=AZ|I|10}} in [[Casa Grande, Arizona|Casa Grande, AZ]]
| states = [[California]], [[Arizona]]
| counties = '''CA:''' [[San Diego County, California|San Diego]], [[Imperial County, California|Imperial]]<br />'''AZ:''' [[Yuma County, Arizona|Yuma]], [[Maricopa County, Arizona|Maricopa]], [[Pinal County, Arizona|Pinal]]
| system1 = {{infobox road/browselinks/USA|state=CA}}
| system2 = {{infobox road/browselinks/USA|state=AZ}}
| browse = {{ca browse|previous_type=CA|previous_route=7|route=CA|next_type=CA|next_route=9}}{{az browse|previous_type=AZ|previous_route=989|route=AZ|next_type=I|next_route=10}}
}}

[[File:San Diego Trolley over Interstate 8.jpg|thumb|right|300px|I-8 in [[San Diego]], from the [[San Diego Trolley]]]]
'''Interstate&nbsp;8''' ('''I-8''') is an [[Interstate Highway System|Interstate Highway]] in the [[southwestern United States]]. It runs from the southern edge of [[Mission Bay (San Diego)|Mission Bay]] at Sunset Cliffs Boulevard in [[San Diego|San Diego, California]], almost at the Pacific Ocean, to the junction with [[Interstate 10 in Arizona|I-10]], just southeast of [[Casa Grande, Arizona]]. In California, the freeway travels through the San Diego metropolitan area as the '''Ocean Beach Freeway''' and the '''Mission Valley Freeway''' before traversing the [[Cuyamaca Mountains]] and providing access through the [[Imperial Valley]], including the city of [[El Centro, California|El Centro]]. Crossing the [[Colorado River]] into [[Arizona]], I-8 continues through the city of [[Yuma, Arizona|Yuma]] across the [[Sonoran Desert]] to Casa Grande, in between the cities of [[Phoenix, Arizona|Phoenix]] and [[Tucson, Arizona|Tucson]].

The first route over the Cuyamaca Mountains was dedicated in 1912, and a [[plank road]] served as the first road across the Imperial Valley to Yuma; east of there, the [[Gila Trail]] continued east to [[Gila Bend, Arizona|Gila Bend]]. These were later replaced by [[U.S. Route&nbsp;80]] (US&nbsp;80) across California and part of Arizona, and [[Arizona State Route&nbsp;84]] (SR&nbsp;84) between Gila Bend and Casa Grande. The US&nbsp;80 freeway through San Diego was largely complete by the time it was renumbered as I-8 in the [[1964 state highway renumbering (California)|1964 state highway renumbering]]; east of San Diego, the US&nbsp;80 roadway was slowly replaced by I-8 as construction progressed in the Imperial Valley. The Arizona portion of the road was built starting in the 1960s. Several controversies erupted during the construction process; questionable labor practices in Imperial County led to the federal conviction of mobster [[Jimmy Fratianno]], and a [[U.S. House of Representatives]] subcommittee found that the Arizona government had mismanaged financial resources.

The route was completed in 1975 through California, and by 1977 through Arizona, though the bridge over the Colorado River was not completed until 1978. Since then, the freeway through San Diego has been widened due to increasing congestion, and another portion in Imperial County had to be rebuilt following damage by the remnants of [[Hurricane Kathleen]].

==Route description==
I-8 is part of the [[National Highway System (United States)|National Highway System]],<ref name=fhwa-nhs>{{FHWA NHS map|region=californiasouth}}</ref><ref name=fhwa-nhsaz>{{FHWA NHS map|region=arizona}}</ref> a network of highways that are considered essential to the country's economy, defense, and mobility by the [[Federal Highway Administration]].<ref name=NHS-FHWA>{{FHWA NHS}}</ref> The freeway from the eastern junction with [[California State Route&nbsp;98]] (SR&nbsp;98) to the eastern end is designated as part of the [[Juan Bautista de Anza National Historic Trail]] auto tour route, promoted by the [[National Park Service]].<ref>{{cite web |url = http://www.solideas.com/DeAnza/TrailGuide/Imperial/index.html |title = Juan Bautista de Anza National Historic Trail Guide: Imperial County |publisher = National Park Service |author = National Park Service |access-date = October 6, 2008 |archive-url = https://web.archive.org/web/20080705234710/http://www.solideas.com/DeAnza/TrailGuide/Imperial/index.html |archive-date = July 5, 2008 |url-status = live }}<br />{{cite web |url = http://www.solideas.com/DeAnza/TrailGuide/Yuma/index.html |title = Juan Bautista de Anza National Historic Trail Guide: Yuma County |publisher = National Park Service |author = National Park Service |access-date = October 6, 2008 |archive-url = https://web.archive.org/web/20081011022552/http://www.solideas.com/DeAnza/TrailGuide/Yuma/index.html |archive-date = October 11, 2008 |url-status = live }}<br />{{cite web |url = http://www.solideas.com/DeAnza/TrailGuide/Maricopa/index.html |title = Juan Bautista de Anza National Historic Trail Guide: Maricopa County |publisher = National Park Service |author = National Park Service |access-date = October 6, 2008 |archive-url = https://web.archive.org/web/20081120024137/http://www.solideas.com/DeAnza/TrailGuide/Maricopa/index.html |archive-date = November 20, 2008 |url-status = live }}<br />{{cite web |url = http://www.solideas.com/DeAnza/TrailGuide/Pinal/index.html |title = Juan Bautista de Anza National Historic Trail Guide: Pinal County |publisher = National Park Service |author = National Park Service |access-date = October 6, 2008 |archive-url = https://web.archive.org/web/20081120023353/http://www.solideas.com/DeAnza/TrailGuide/Pinal/index.html |archive-date = November 20, 2008 |url-status = live }}</ref>

{{Anchor|California}}

===San Diego to Arizona border===
The entirety of Interstate 8 in California is defined in the California Streets and Highways Code as '''Route 8''', whose definition in section 308 is as follows<ref>[https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=SHC&sectionNum=308. California Code, SHC 308.]</ref>:<blockquote>Route 8 is from:<br>(a) Sunset Cliffs Boulevard to [[Interstate 5 in California|Route 5]] in San Diego<br>(b) Route 5 in San Diego to Yuma via El Centro.</blockquote>
The freeway begins at the intersection of Sunset Cliffs Boulevard and Nimitz Boulevard in [[San Diego]]. For its first few miles, it parallels the [[San Diego River]] floodway. Near [[Old Town, San Diego|Old Town San Diego]], I-8 intersects with I-5 as well as with Rosecrans Street, the former routing of [[California State Route 209|SR&nbsp;209]].<ref name="tgsd2">{{cite map |author = Thomas Brothers |location = Irvine, CA |publisher = Thomas Brothers |title = San Diego County Road Atlas |year = 1998 |page = 1232 |isbn = 0-88130-902-8 |oclc = 38909538 |scale = 1:316,800 }}</ref> Even though the freeway west of I-5 is signed with interstate shields, it is not considered a chargeable interstate highway according to Federal Highway Administration route logs, which defines I-8's western terminus at I-5.<ref>{{cite web | url=https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/table01.cfm | title=Table 1 - Main Routes - FHWA Route Log and Finder List - Interstate Highway System - National Highway System - Planning - FHWA }}</ref> Under regular circumstances, the [[California Department of Transportation]] (Caltrans) would sign this freeway segment as State Route 8.

As the freeway enters [[Mission Valley, San Diego|Mission Valley]], it continues eastward, bisecting the area known as "Hotel Circle" that has several hotels.  I-8 then has interchanges with [[California State Route 163|SR&nbsp;163]], [[Interstate 805|I-805]], and [[Interstate 15 in California|I-15]]. In [[La Mesa, California|La Mesa]], the route intersects [[California State Route 125|SR&nbsp;125]], and in [[El Cajon, California|El Cajon]]  it intersects with [[California State Route 67|SR&nbsp;67]]. From Mission Valley through El Cajon, it is paralleled by the [[San Diego Trolley]] [[Green Line (San Diego Trolley)|Green Line]].

East of El Cajon, it ascends into the mountains and the [[Cleveland National Forest]], traveling through towns such as [[Alpine, California|Alpine]] then going by the [[Viejas Casino]] before reaching [[Pine Valley, California|Pine Valley]]. This route achieves four 4,000-foot (1219.2 meters) high points at [[Carpenter Summit]], then crosses the [[Pine Valley Creek Bridge]] before the [[Laguna Summit]], followed by the [[Crestwood Summit]], then the [[Tecate Divide]],<ref name="acme" /> After the Laguna Summit, the road passes a [[United States Border Patrol interior checkpoints|U.S. border patrol interior checkpoint]] that was constructed in 1995 near Buckman Springs Road turnoff just east of the summit.<ref>{{Cite news |title = Border Patrol Will Open Checkpoint on I-8 |last = Sanchez, Leonel |date = October 19, 1995 |work = San Diego Union-Tribune |page = A1 |oclc = 25257675 }}</ref> However, this resulted in smugglers driving the wrong way on I-8 at high speeds in order to avoid the checkpoint, causing several crashes, even after concrete barriers were installed.<ref>{{Cite news |title = State Asked for Barriers to Stop I-8 Cross-overs |last = Vigil, Jennifer |date = September 21, 2003 |work = San Diego Union-Tribune |page = B1 |oclc = 25257675 }}</ref><ref>{{Cite news |title = Smugglers Make East County Highways Deadly |date = October 13, 2005 |work = San Diego Union-Tribune |page = B13 |oclc = 25257675 }}</ref> The freeway intersects with [[California State Route 79|SR&nbsp;79]] in the national forest before passing through the [[La Posta Indian Reservation|La Posta]] and [[Campo Indian Reservation|Campo]] Indian reservations.

In [[Boulevard, California|Boulevard]], I-8 has an interchange with the eastern end of [[California State Route 94|SR&nbsp;94]].<ref name="tgsd">{{cite map |author = Thomas Brothers |location = Irvine, CA |publisher = Thomas Brothers |title = San Diego County Road Atlas |year = 2009 |pages = 429–430, 1232–1237, 1251–1252, 1268–1270, 1298–1300 |isbn = 978-1-58174-110-0 |oclc = 263420904 }}</ref><ref name="rmcn">{{cite map |author = Rand McNally |title = The Road Atlas: United States, Canada, and Mexico |year = 2008 |location = Chicago |publisher = Rand McNally |page = 15 |isbn = 978-0-528-93961-7 |oclc = 173493291 |scale = c. 1:1.584,000 }}<br />{{cite map |author = Rand McNally |title = The Road Atlas: United States, Canada, and Mexico |year = 2008 |location = Chicago |publisher = Rand McNally |page = 17 |isbn = 978-0-528-93961-7 |oclc = 173493291 |scale = c. 1:190,080 |inset = San Diego }}</ref>

I-8 straddles the [[San Diego County, California|San Diego]]–[[Imperial County, California|Imperial]] county line for a few miles before turning east. At the Mountain Springs/In-Ko-Pah grade, the freeway is routed down two separate canyons—[[Devils Canyon (Jacumba Mountains)|Devils Canyon]] for westbound traffic and [[In-Ko-Pah Gorge]] for eastbound traffic—as it descends {{convert|3000|ft|m|abbr=on}} in {{convert|11|mi|km|abbr=on}}.<ref name="acme">{{cite map |url = http://mapper.acme.com/?ll=32.69646,-116.08944&z=13&t=T&marker0=41.19886%2C-120.94414 |title = Acme Mapper |publisher = Acme Maps |access-date = April 28, 2013 |author = OpenStreetMap |archive-url = https://web.archive.org/web/20140714165023/http://mapper.acme.com/?ll=32.69646,-116.08944&z=13&t=T&marker0=41.19886%2C-120.94414 |archive-date = July 14, 2014 |url-status = live }}</ref> In places, the median is over {{convert|1.5|mi|km|abbr=on}} wide.<ref name="rmcn"/><ref name="tg">{{cite map |author = Thomas Brothers |location = Irvine, CA |publisher = Thomas Brothers |title = California Road Atlas and Driver's Guide |year = 2000 |pages = 107, 111, 112, 212, 213, 214, V |oclc = 41359350 }}</ref> This portion of the road is known for high winds through the canyons that have made driving difficult, sometimes resulting in closure of the freeway;<ref name="grade"/> in 1966, the [[California Highway Patrol]] estimated that winds blew at speeds of up to {{convert|100|mph|km/h|abbr=on}}.<ref>{{cite news |title = Screen To Curb Devilish Wind |work = The San Diego Union |date = March 8, 1966 |author = Hudson, Ken |page = A17 |oclc = 13155544 }}</ref> The route enters the Imperial Valley, where it intersects with SR&nbsp;98, a highway leading to [[Calexico, California|Calexico]], and passes near the [[Desert View Tower]]. I-8 then goes through [[Ocotillo, California|Ocotillo]] and [[Coyote Wells, California|Coyote Wells]] before entering the city of [[El Centro, California|El Centro]] several miles later.<ref name="rmcn"/><ref name="tg"/>

In El Centro, I-8 intersects with [[California State Route 86|SR&nbsp;86]] and [[California State Route 111|SR&nbsp;111]], both north–south routes which connect to [[Interstate 10 in California|I-10]] in the [[Coachella Valley]], north of the [[Salton Sea]]. [[California State Route 115|SR&nbsp;115]] and SR&nbsp;98 end at I-8 east of El Centro. The route also has the lowest above-ground elevation of any Interstate at {{convert|52|ft|m|abbr=on}} [[below sea level]] near El Centro.<ref name="fhwaoldfact">{{cite web |url = https://highways.dot.gov/highway-history/interstate-system/50th-anniversary |title = Previous Interstate Facts of the Day |publisher = Federal Highway Administration |work = Celebrating the Eisenhower Interstate Highway System |date = February 29, 2012 |access-date = September 29, 2012 |author = Federal Highway Administration |archive-url = https://web.archive.org/web/20060426084506/http://www.fhwa.dot.gov/interstate/previousfacts.cfm |archive-date = April 26, 2006 |url-status = live }}</ref> The freeway then traverses the [[Imperial Sand Dunes Recreation Area]] and intersects with [[California State Route 186|SR&nbsp;186]] leading south to [[Baja California Norte]], Mexico.<ref name="rmcn"/><ref name="tg"/> I-8 runs parallel to the [[All-American Canal]] across the desert for roughly {{convert|55|mi|km|abbr=on}}.<ref>{{harvp|Pittman|1995|p=341}}.</ref> At points in eastern Imperial County, the [[Mexico–United States border|Mexican border]] is less than {{convert|0.5|mi|km|abbr=on}} south of the Interstate. I-8 then passes through [[Felicity, California|Felicity]] and [[Winterhaven, California|Winterhaven]] before crossing the [[Colorado River]] on a bridge into [[Yuma, Arizona]].<ref name="rmcn"/><ref name="tg"/>

I-8 is part of the [[California Freeway and Expressway System]]<ref name="cafes">{{CAFESystem}}</ref> and is eligible for the [[State Scenic Highway System (California)|State Scenic Highway System]] from [[Interstate 5 in California|I-5]] to the western junction of SR&nbsp;98,<ref name="scenic">{{CA scenic}}</ref> though it is not an official state scenic highway.<ref name="actualscenic">{{Caltrans scenic|access-date=December 14, 2016}}</ref> It is officially known as the Border Friendship Route from San Diego to the Arizona state line. The Interstate is signed as the Ocean Beach Freeway west of I-5. For the entire length within San Diego County and into Imperial County, it is signed as the Kumeyaay Highway, after [[Kumeyaay people|the local Native American tribe]] and their traditional trade route which the Interstate follows.<ref>{{CA Named Freeways |pages=15, 289}}</ref><ref>{{Cite book |first1 = Geralyn Marie |last1 = Hoffman |first2 = Lynn H. |last2 = Gamble |author3 = San Diego State University Institute for Regional Studies of the Californias |year = 2006 |url = https://books.google.com/books?id=rfg4TOb4o10C&pg=PA24 |title = A Teacher's Guide to Historical and Contemporary Kumeyaay Culture |location = San Diego |publisher = San Diego State University Institute for Regional Studies of the Californias |page = 24 |isbn = 978-0-925613-51-6 |oclc = 173480703 |access-date = October 10, 2016 |archive-url = https://web.archive.org/web/20161130215433/https://books.google.com/books?id=rfg4TOb4o10C&pg=PA24 |archive-date = November 30, 2016 |url-status = live }}</ref> Between Old Town and El Cajon, I-8 is called the Mission Valley Freeway.<ref name="tg"/> In 2014, I-8 had an [[annual average daily traffic]] (AADT) of 11,800&nbsp;vehicles between Bonds Corner Road and SR&nbsp;115, as well as between SR&nbsp;98 and Imperial Highway, and 239,000&nbsp;vehicles between I-805 and I-15, the latter of which was the highest AADT for the highway in California.<ref name=traffic>{{Caltrans traffic|year=2014|start=7|end=10|access-date=December 14, 2016}}</ref>

{{anchor|Arizona}}

===Yuma to Casa Grande===
[[File:3-line distance sign, I-8, Gila Bend, AZ.jpg|thumb|left|A sign displaying the mileages on I-8 westbound in Gila Bend]]
I-8 enters Arizona from California at the Colorado River bridge at Yuma. It initially heads south through Yuma until the interchange with [[U.S. Route 95 in California|US&nbsp;95]], where the freeway begins to turn to the east and passes through eastern Yuma and [[Fortuna Foothills, Arizona|Fortuna Foothills]], briefly paralleling US&nbsp;95 and passing through a second border inspection station. In the [[Gila Mountains (Yuma County)|Gila Mountains]], the eastbound lanes of I-8 cross under the westbound freeway, briefly traveling to the left near Telegraph Pass before reverting. West of [[Wellton, Arizona|Wellton]], the highway takes a northeasterly course, paralleling the [[Gila River]] and passing to the south of [[Roll, Arizona|Roll]]. Through this part of Arizona, I-8 passes along the northern edge of the [[Barry M. Goldwater Air Force Range]] and to the south of the [[Yuma Proving Ground]]. It keeps a northeastern heading, passing through the community of [[Dateland, Arizona|Dateland]], until it reaches [[Gila Bend, Arizona|Gila Bend]]. There, the freeway intersects [[Arizona State Route 85|SR&nbsp;85]] heading north to [[Phoenix, Arizona|Phoenix]] and south to the [[Organ Pipe Cactus National Monument]].<ref name="ADOT Highway Log"/><ref name="googleAZ"/>

After leaving Gila Bend, I-8 takes a southeastern course as it passes through the [[Sonoran Desert National Monument]]. Exiting the national monument grounds, the highway continues on an easterly bearing to a junction with [[Arizona State Route 84|SR&nbsp;84]], a highway that parallels I-8 to the north and goes through [[Casa Grande, Arizona|Casa Grande]], while I-8 passes to the south of both [[Stanfield, Arizona|Stanfield]] and Casa Grande. I-8 reaches its eastern terminus southeast of [[Casa Grande Mountain Park]] at an interchange with [[Interstate 10 in Arizona|I-10]], which continues north (westbound) to [[Phoenix, Arizona|Phoenix]], and south (eastbound) to [[Tucson, Arizona|Tucson]].<ref name="ADOT Highway Log"/><ref name="googleAZ">{{google maps |url=https://maps.google.com/maps?f=d&hl=en&geocode=12292208217460437544,32.728310,-114.617480%3B401209425362210788,32.817011,-111.683029&saddr=I-8+E+%4032.728310,+-114.617480&daddr=Exit+178A+%4032.817011,+-111.683029&doflg=ptm&sll=32.795685,-113.150255&sspn=3.181171,5.119629&ie=UTF8&z=8 |title=Overview Map of I-8 in Arizona |access-date=April 11, 2008 |link=no}}</ref>

The combination of SR&nbsp;85 between I-10 and I-8 as well as I-8 between SR&nbsp;85 and I-10 in Casa Grande has been promoted as a bypass of the Phoenix area for long-distance travelers on I-10.<ref name="sign">{{cite sign |author = Arizona Department of Transportation |url = http://commons.wikimedia.org/wiki/File:Interstate_8_Eastern_Terminus.jpg |title = Exit&nbsp;200 eastbound overhead |medium = Highway guide sign |location = Casa Grande, AZ |publisher = Arizona Department of Transportation |access-date = October 27, 2012 |archive-url = https://web.archive.org/web/20141220121322/http://commons.wikimedia.org/wiki/File:Interstate_8_Eastern_Terminus.jpg |archive-date = December 20, 2014 |url-status = live }}</ref> In 2014, I-8 had an AADT of 5,200&nbsp;vehicles between Butterfield Trail and Freeman Road, and 44,400&nbsp;vehicles between [[Arizona State Route 280|SR&nbsp;280]] and Araby Road east of Yuma, the latter of which was the highest AADT for the highway in Arizona.<ref name=AZtraffic>{{cite web |title = Average Annual Daily Traffic |author = Arizona Department of Transportation |url = http://azdot.gov/docs/default-source/planning/2014-interstates-aadt.pdf?sfvrsn=2 |format = PDF |publisher = Arizona Department of Transportation |year = 2014 |access-date = December 14, 2016 |archive-url = https://web.archive.org/web/20170329213143/http://azdot.gov/docs/default-source/planning/2014-interstates-aadt.pdf?sfvrsn=2 |archive-date = March 29, 2017 |url-status = live }}</ref> In the early 2010s, I-8 from Casa Grande to Gila Bend was sometimes used for smuggling both drugs and humans.<ref>{{Cite news |url = http://www.azcentral.com/news/articles/2011/01/29/20110129arizona-smuggling-on-interstate-8.html |title = Arizona, Federal Officials Target Smugglers on Interstate 8 |last = Collom, Lindsey |date = January 29, 2011 |work = The Arizona Republic |location = Phoenix |oclc = 2609778 |access-date = June 21, 2014 }}</ref>

==History==
The I-8 designation was accepted as a [[Interstate Highway System#Chargeable and non-chargeable Interstate routes|chargeable Interstate]] by the [[American Association of State Highway Officials]] in 1957,<ref name=I1957>{{cite map |author = Public Roads Administration |location = Washington, DC |scale = Scale not given |publisher = Public Roads Administration |date = August 14, 1957 |title = Official Route Numbering for the National System of Interstate and Defense Highways as Approved by the American Association of State Highway Officials |url = http://commons.wikimedia.org/wiki/File:Interstate_Highway_plan_August_14,_1957.jpg |access-date = April 4, 2012 |archive-url = https://web.archive.org/web/20121110055957/http://commons.wikimedia.org/wiki/File:Interstate_Highway_plan_August_14,_1957.jpg |archive-date = November 10, 2012 |url-status = live }}</ref> and was added to the state highway system in 1964 by the [[California State Legislature]]; the US&nbsp;80 designation was removed at that time.<ref name="renumbering">{{cite journal |url = http://www.gbcnet.com/ushighways/history/1964_route_renumbering.pdf |title = Route Renumbering: New Green Markers Will Replaces Old Shields |journal = California Highways and Public Works |date = March–April 1964 |volume = 43 |issue = 1–2 |pages = 11–14 |issn = 0008-1159 |oclc = 7511628 |access-date = March 8, 2012 |archive-url = https://web.archive.org/web/20130619023353/http://www.gbcnet.com/ushighways/history/1964_route_renumbering.pdf |archive-date = June 19, 2013 |url-status = live }}</ref><ref name="cite1963">{{cite CAstat|year=1963|ch=385}}</ref>

===San Diego area===
The freeway that would become I-8 was constructed in the mid-20th century through the San Diego area. The section west of I-5 was originally part of SR&nbsp;109, and was added to I-8 in 1972. In later years, the [[California Department of Transportation]] (Caltrans) made efforts to widen the freeway as congestion increased.

====Initial construction====
{{see also|U.S. Route 80 in California}}
Much of Alvarado Canyon Road from San Diego to La Mesa was originally built between 1947 and 1950, a bypass of the old US&nbsp;80 routing along El Cajon Boulevard and La Mesa Boulevard.<ref name="chpw">{{cite journal |title = Alvarado Canyon |author = Mack, Joseph |journal = California Highways and Public Works |date = May–June 1950 |volume = 29 |issue = 4 |pages = 42–43 |oclc = 7511628 }}</ref> Work began to convert the original US&nbsp;80 [[divided highway]] into a freeway in 1960,<ref>{{Cite news |title = State Asks Bids For Link in U.S. 80 Project Here |date = January 6, 1959 |work = The San Diego Union |page = A13 |oclc = 13155544 }}</ref> and the freeway was complete west of El Cajon by April 1962.<ref>{{Cite news |title = Freeway Link Opens Tomorrow on U.S.&nbsp;80 |date = April 23, 1962 |work = The San Diego Union |page = A18 |oclc = 13155544 }}</ref> Priority was given to planning US 80 in 1962 by the [[California Chamber of Commerce]].<ref>{{cite news |title = State C of C Urges New Roads in Area |work = The San Diego Union |date = August 23, 1962 |page = C17 |oclc = 13155544 }}</ref> In 1964, I-8 was officially designated by the California State Legislature, and the US 80 designation was removed.<ref name="renumbering"/><ref name="cite1963"/> By 1965, I-8 from Fairmount Avenue to El Cajon Boulevard was one of the first freeway stretches in the county to have a center barrier installed in the median.<ref>{{cite news |title = More Freeway Center Barriers Are Planned |work = The San Diego Union |date = January 7, 1965 |last = Brooks |first = Joe |page = A21 |oclc = 13155544 }}</ref>

The Ocean Beach Freeway section west of I-5 was authorized as Route&nbsp;286 in 1959.<ref name="CA1959">{{cite CAstat |year=1959 |ch=1062 }}</ref> In 1962, four alternate routes were proposed for this part of the freeway, and for Rosecrans Street.<ref>{{cite news |title = Alternate Routes Studied For Midway Area Freeways |work = The San Diego Union |date = August 27, 1962 |page = A17 |oclc = 13155544 }}</ref> Route&nbsp;286 was renumbered to SR&nbsp;109 in the 1964 renumbering.<ref name="cite1963"/> Plans for the Old Town interchange between I-5 (formerly US&nbsp;101), I-8 (formerly US&nbsp;80), SR&nbsp;209 (Rosecrans Street), and SR&nbsp;109 date from 1962, although several concerns had to be taken into account, including the preservation of historical [[Old Town, San Diego|Old Town]] and keeping traffic through the area moving during construction. The goal was to begin the process in 1966, and complete the interchange in 1969.<ref>{{cite news |title = Light Industry Center Urged For Midway-Frontier Area |work = The San Diego Union |date = August 15, 1962 |page = A17 |oclc = 13155544 }}</ref><ref>{{Cite news |title = $11&nbsp;Million Interchange Projected |date = March 16, 1965 |work = The San Diego Union |page = A15 |oclc = 13155544 }}</ref> There were concerns about a $3&nbsp;million shortfall in funding (about ${{Formatprice|{{Inflation|US-GDP|3000000|1966|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} during May 1966, which caused the San Diego Chamber of Commerce Highway Committee to recommend the completion of SR&nbsp;109 as a project.<ref>{{cite news |title = Fund Loss Feared For State Highways Under Transit Plan |work = The San Diego Union |date = May 11, 1966 |page = A22 |oclc = 13155544 }}</ref> This was projected to be the final highway project before I-5 was completed in San Diego County.<ref>{{cite news |title = Interstate 5 Will Have 36 Interchanges For Easy Travel |work = The San Diego Union |date = August 1, 1966 |last = James |first = Paul |page = B1 |oclc = 13155544 }}</ref>

The building phase started on September 22, 1966, on the interchange that was to replace the intersection of Pacific Highway and Rosecrans Street. The cost of the interchange was projected to be $10.86&nbsp;million<ref>{{cite news |title = 'Stack' Like Plate Of Spaghetti |work = The San Diego Union |date = March 26, 1967 |last = Brown |first = Joe |page = B1 |oclc = 13155544 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|10860000|1967|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} SR&nbsp;109 was planned to follow Camino del Rio up to the Frontier traffic circle, where the city of San Diego would resume construction; both SR&nbsp;109 and SR&nbsp;209 were to be built in the future.<ref>{{Cite news |title = $11&nbsp;Million Interchange To Link Freeways |date = December 4, 1966 |work = The San Diego Union |page = B4 |oclc = 13155544 }}</ref> The eight-lane freeway was projected to relieve traffic in the Frontier Street area coming from the [[Pechanga Arena|San Diego Sports Arena]]. [[Construction bidding|Bidding]] for the SR&nbsp;109 contract was to begin in 1968, after the City Council endorsed the route in December 1967. Completion of both the interchange and SR&nbsp;109 was planned for early 1969.<ref name="feb">{{cite news |title = Interstate 5 and 8 Ramps to Close |work = The San Diego Union |date = February 27, 1968 |page = C1 |oclc = 13155544 }}</ref> An interchange was planned at Midway Drive, and the western end of the freeway was to be at Sunset Cliffs and Nimitz boulevards.<ref>{{cite news |title = Council Approves 109 Freeway Route |work = The San Diego Union |date = December 29, 1967 |page = B3 |oclc = 13155544 }}</ref> The cost of the SR&nbsp;109 project was estimated to be $2.3&nbsp;million<ref name="obgb">{{cite news |title = Ground Broken For Beach Freeway |work = The San Diego Union |date = September 24, 1968 |page = C3 |oclc = 13155544 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|2300000|1968|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}}

<!--[[File:Interstate8SD.jpg|thumb|right|Interstate 8 in San Diego near Mission Valley]]-->
The ramp from south I-5 to Camino del Rio opened in February 1968,<ref name="feb"/> and a second ramp from southbound I-5 to eastbound I-8 opened in August 1968, with the remainder of the project to be completed in summer 1969.<ref>{{cite news |title = Interstate 5–8 Revisions Due On Monday |work = The San Diego Union |date = August 3, 1968 |page = B1 |oclc = 13155544 }}</ref> The groundbreaking for the Ocean Beach Freeway took place on September 23, 1968, with the estimated completion to take place within 15 months.<ref name="obgb"/> However, rain in February 1969 delayed many construction projects across the county, including the SR&nbsp;109 extension.<ref>{{cite news |title = 2,000 To 3,000 Building Men Idled By Rain |work = The San Diego Union |date = February 25, 1969 |last = Clance |first = Homer |page = B8 |oclc = 13155544 }}</ref> The entire project was completed in September, with the road scheduled to open in October.<ref>{{Cite news |title = Dedication of Ocean Beach Freeway Slated |last = Scarr |first = Lew |date = September 26, 1969 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref> The routing of SR&nbsp;109 was officially added to I-8 in 1972.<ref>{{cite CAstat|year=1972|ch=1216}}</ref>

====Subsequent expansion====
Even before the freeway was complete in California, bidding began in 1964 on widening I-8 from six to eight lanes between near Fairmount Avenue and Spring Street, in San Diego and La Mesa.<ref>{{cite news |title = Bids on 4 Southland Road Projects Called |work = Los Angeles Times |date = March 24, 1964 |page = 22 |oclc = 3638237 }}</ref> Three years later, a contract was granted for the widening of the Fairmount Avenue to Ward Road stretch, adding two lanes to the freeway.<ref>{{cite news |title = Contract Let For Widening of Interstate 8 |work = The San Diego Union |date = March 31, 1967 |page = B11 |oclc = 13155544 }}</ref> In 1974, the San Diego City Council reached an agreement with state officials to improve I-8 from east of Pacific Highway to Texas Street, over the objections of Councilman Floyd Morrow, who objected to solving traffic issues by continuing to expand freeways. The cost was estimated to be $8&nbsp;million<ref>{{cite news |title = I-8 Freeway Improvement Pact OKd |work = The San Diego Union |date = February 20, 1974 |page = B4 |oclc = 13155544 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|8000000|1974|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}}

The La Mesa City Council asked the state to modify the interchange with SR&nbsp;125 in 1974; the original interchange did not allow for access to SR&nbsp;125 from I-8 east or to I-8 west from SR&nbsp;125.<ref>{{cite news |title = City Asks Interchange Construction |work = The San Diego Union |date = July 25, 1974 |author = Staff |page = B3 |oclc = 13155544 }}</ref> Widening of the portion from SR&nbsp;125 to El Cajon Boulevard to five lanes in each direction was under way in October.<ref>{{cite news |title = Roadwork Begins In Area |work = The San Diego Union |date = October 31, 1974 |page = B3 |oclc = 13155544 }}</ref> By 1981, the [[environmental impact report]] had been completed, and the $50&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|50000000|1981|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} project to add ramps and widen I-8 was awaiting clearance from the [[Federal Highway Administration]].<ref>{{cite news |title = Interchange Project Nears Green Light |work = The San Diego Union |date = May 20, 1981 |page = B3 |oclc = 13155544 }}</ref> Additional ramps to SR&nbsp;67 were nearing completion in May&nbsp;1985,<ref>{{Cite news |title = El Cajon Freeway Ramps to Open Soon |last = Grimaldi, James |date = May 30, 1985 |work = Evening Tribune |page = B6 |oclc = 37687666 }}</ref> and were completed to I-15 north in October.<ref>{{Cite news |title = Ramps are Opened Between Northbound I-15 and I-8 |last = Jahn, Ed |date = October 25, 1985 |work = The San Diego Union |page = B2 |oclc = 13155544 }}</ref> In 1986, the project revamping the SR&nbsp;125 interchange was under way, at a cost of $80&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|80000000|1986|r=-6}}}} in {{inflation-year|US-GDP}} dollars);{{Inflation-fn|US-GDP}} it would add two more lanes to I-8 from Jackson Drive to Fuerte Drive, and allow for SR&nbsp;125 to be extended north past I-8.<ref>{{Cite news |title = Detour-Sign Watchers Have Field Day at Interchange |last = Taylor, Kathie |date = December 5, 1986 |work = Evening Tribune |page = B22 |oclc = 37687666 }}</ref>

By 1977, traffic had reached 172,300&nbsp;vehicles a day, which had increased by nearly 10&nbsp;percent over the previous year. It was hoped that the construction of [[California State Route 52|SR&nbsp;52]] would help to reduce the congestion.<ref>{{cite news |title = Traffic Congestion Plagues Interstate 8 |work = The San Diego Union |date = May 1, 1977 |author = Hudson, Ken |page = B1 |oclc = 13155544 }}</ref> A revised Mission Gorge Road eastbound exit opened in 1979, merging with traffic from I-15.<ref>{{cite news |title = New Mission Gorge Exit on I-8 to Open Today |work = Los Angeles Times |date = August 23, 1979 |page = SD A10 |oclc = 3638237 }}</ref> Traffic reached 212,000&nbsp;vehicles a day by February&nbsp;1981, and Caltrans declared I-8 east of I-805 the busiest highway in the region.<ref>{{Cite news |title = CalTrans Study Says Interstate 8 Stretch is Busiest Artery in Area |last = Fuentes, Henry |date = April 20, 1984 |work = The San Diego Union |page = B3 |oclc = 13155544 }}</ref> In 1987, Caltrans determined that I-8 west between College Avenue and Waring Road had the highest ratio of cars to number of lanes worldwide, at 2400&nbsp;cars per hour.<ref>{{Cite news |title = Interstate 8 from College Avenue to Waring is the Amazon of Freeways |last = Okerblom, Jim |date = September 20, 1987 |work = The San Diego Union |page = B6 |oclc = 13155544 }}</ref> Plans to add another lane to I-8 west from College Avenue to I-15 began in March&nbsp;1992.<ref>{{Cite news |title = Lane-Widening May Snarl Traffic on I-8 |last = Kucher, Karen |date = March 3, 1992 |work = San Diego Union-Tribune |page = B1 |oclc = 25257675 }}</ref>

Caltrans proposed the installation of a metered [[traffic signal]] on I-8 west in Lakeside during 1987, in order to improve traffic flow in the mornings by inserting a short delay before entering San Diego should the rate exceed 2,000&nbsp;vehicles per hour.<ref>{{Cite news |title = Stoplight on I-8 May Ease Traffic |last = Okerblom, Jim |date = October 28, 1987 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref> However, the state put its plans on hold shortly thereafter, following several concerns from the public, and from state senator Jim Ellis.<ref>{{Cite news |title = Stoplight Turned Red by Protests |last = Carson, Daniel |date = October 29, 1987 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref>

===Cuyamaca Mountains===
{{see also|U.S. Route 80 in California}}

====Early road====
[[Image:Old US 80 West of Descanso Junction.JPG|thumb|left|A section of old US&nbsp;80 (Wildwood Glen Lane) now closed to vehicular traffic west of [[Descanso, California|Descanso Junction]]]]

A [[stagecoach road]] existed into the 19th&nbsp;century that passed through the mountains east of San Diego.<ref name="grade">{{cite news |title = I-8 grade challenges the motorist |work = The San Diego Union |date = May 9, 1985 |last = McVicar |first = Jim |page = II7 |oclc = 13155544 }}</ref> Before the freeway was constructed, the automobile road through the mountains east of San Diego was narrow and wound through the mountains; it was officially dedicated in 1912.<ref name="fruition">{{cite news |title = San Diego-Yuma Freeway Dream Nearing Fruition |work = The San Diego Union |date = May 19, 1970 |last = McVicar |first = Jim |page = B3 |oclc = 13155544 }}</ref><ref name="newroadlink"/> This trip was known to take up to four hours, and frequently resulted in the [[Radiator#Engine cooling|radiator]] boiling over, flat tires, or broken [[fan belt]]s; inclement weather would result in cars becoming mired in the mud. The road was paved in 1926, and was open by 1927; remnants of this road were still present in the late 20th&nbsp;century. Another road was built in the early 1930s, to remove curves and widen the lanes.<ref name="grade"/> This was a two-lane road that still had many [[hairpin turn|switchbacks]], with one popularly known as "Dead Man's Curve".<ref>{{cite news |title = Out of Way-side Ellis Rest stop still remembered |work = The San Diego Union |date = March 7, 1985 |last = McVicar |first = Jim |page = B4 |oclc = 13155544 }}</ref> Construction of I-8 took place atop much of the roadbed of the highway from the early 1930s.<ref name="grade"/> The delay in extending a road to San Diego caused increased development in Los Angeles and resulted in that city becoming the trade and population center of Southern California, according to the ''[[San Diego Union-Tribune|San Diego Union]]''.<ref name="finally">{{cite news |title = Last Section Of Interstate 8 To Yuma Opens Thursday |work = The San Diego Union |date = May 25, 1975 |last = Harrison |first = Donald |page = B10 |oclc = 13155544 }}</ref>

====Planning and construction====
Completion of the freeway was the second highest priority according to the Highway Development Association in May 1963, after the I-5 freeway.<ref>{{cite news |title = Top Priority Urged On S.D, Oceanside Freeway Sections |work = The San Diego Union |date = May 28, 1963 |page = A18 |oclc = 13155544 }}</ref> Bidding began on the portion from Broadway in El Cajon to Harritt Road in September 1963. This section of the freeway was to parallel [[U.S. Route 80 in California|US&nbsp;80]] to the south up to Lakeview Road, and then to the north.<ref>{{Cite news |title = Bids For US&nbsp;80 Extension Asked |date = September 24, 1963 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref> This portion of the freeway was scheduled to be complete by May 1965.<ref>{{cite news |title = San Diego County Freeway System |work = The San Diego Union |date = February 22, 1965 |page = A3 |oclc = 13155544 }}</ref> By January 1965, I-8 had been completed from I-5 east to an interchange with Lake Jennings Park Road,<ref>{{cite news |title = Freeway System Big, Growing |work = The San Diego Union |date = January 7, 1965 |last = Van Denburgh |first = Russell |page = C6 |oclc = 13155544 }}</ref> just south of the latter's intersection with the southern terminus of Harritt Road.<ref name="tgsd"/> At a cost of $3.44&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|3446265|1965|r=-6}}}} in {{inflation-year|US-GDP}} dollars),{{Inflation-fn|US-GDP}} the project reduced the grade and curves at what was known as "Tunnel Hill" that hindered the flow of traffic.<ref>{{cite journal |title = I-8 East of El Cajon |author = California Division of Highways |journal = California Highways and Public Works |date = September 1965 |volume = 44 |issue = 5 |pages = 40–41 |oclc = 7511628 }}</ref> The part of the freeway from west of Harritt Road to west of Alpine was up for bidding in October 1964,<ref>{{cite news |title = State To Ask Bids On Alpine Road Link |work = The San Diego Union |date = October 13, 1964 |page = B1 |oclc = 13155544 }}</ref> and the Highway Commission set aside $2.1&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|2100000|1964|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} for this {{convert|1.6|mi|km|adj=mid|-long}} stretch in February 1965.<ref>{{cite news |title = Money For Freeway West Of Alpine OKd |work = The San Diego Union |date = February 25, 1965 |author = Staff |page = A33 |oclc = 13155544 }}</ref> A contract for $1.42&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|1420000|1965|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} was issued in August 1965.<ref>{{cite news |title = State Awards Freeway Job |work = The San Diego Union |date = August 7, 1965 |page = B20 |oclc = 13155544 }}</ref> The entire {{convert|6|mi|km|adj=on}} stretch from Lake Jennings Road to Harbison Canyon Road was under construction by September 1965 and was scheduled to be complete by the next year.<ref>{{cite news |title = Work Set To Start On New Freeway Link |work = The San Diego Union |date = September 29, 1965 |page = A21 |oclc = 13155544 }}</ref>

In the Mountain Springs pass between San Diego and Imperial counties, the eastbound lanes traverse the pass on the former roadbed of US&nbsp;80 through [[In-Ko-Pah Gorge]] near [[Myer Creek (Coyote Wash tributary)|Myers Creek]]. The westbound lanes were placed on a different routing through [[Devils Canyon (Jacumba Mountains)|Devil's Canyon]] that had been constructed by November 1963. A contract for paving the {{convert|9.7|mi|km}} from the San Diego–Imperial county line to SR&nbsp;98, including the eastbound lanes, was given to the Isbell Construction Company for $3.69&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|3690000|1963|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} in May 1963. This portion was completed in May 1965 "through some of the most rugged, hottest sections of San Diego and Imperial counties," according to ''The San Diego Union''. Construction ran into difficulties following concerns regarding potential landslides. The westbound lanes were built first, and temporarily contained both directions of traffic while the old highway was converted into the eastbound lanes.<ref name="lowroadbid">{{Cite news |title = State Reviews Low Road Bid For US&nbsp;80 |date = November 13, 1963 |work = The San Diego Union |page = A17 |oclc = 13155544 }}</ref><ref>{{cite news |title = Jacumba Grade Opens Tomorrow |work = The San Diego Union |date = May 2, 1965 |page = A22 |oclc = 13155544 }}</ref> The ''[[Los Angeles Times]]'' described the stretch east of Mountain Springs as follows: "Through it the freeway engineers have hacked two separate roadways not even in sight of each other, but so overpowering in the sheer magnitude of the cuts through the mountains that it is almost impossible to believe human beings could have so overpowered hostile nature&nbsp;...."<ref name="jacumba">{{cite news |title = Jacumba Ready For Big Moment |work = Los Angeles Times |date = May 22, 1966 |last = Ainsworth |first = Ed |page = F6 |oclc = 3638237 }}</ref> Access to the site for construction workers was difficult, and many slopes had to be stabilized. Temperatures reached {{convert|120|F|C}} in the summer and {{convert|4|F|C}} in winter, with winds reaching up to {{convert|80|mph|km/h|abbr=on}}.<ref>{{cite journal |title = Mountain Springs Grade |author = California Division of Highways |journal = California Highways and Public Works |date = January 1964 |volume = 43 |issue = 1 |pages = 43–44 |oclc = 7511628 }}</ref> While [[Project Plowshare|using nuclear explosions to conduct blasting operations]] in the Laguna Mountains was considered as a possibility, the proposal was not considered to be practical at the time.<ref>{{Cite news |title = Atom Blasts Won't Build New US&nbsp;80 |last = Zimmerman, Robert |date = March 26, 1963 |work = The San Diego Union |page = A11 |oclc = 13155544 }}</ref> Two cables and a hook were used to move girders into place; this was the first use of a cable in Southern California road construction.<ref>{{cite news |title = Steel Is Taming Devil's Canyon |work = The San Diego Union |date = March 9, 1963 |author = Kaye, Peter |page = A1 |oclc = 13155544 }}</ref>

The portion from Boulevard to near the Imperial County line was included in the California Highway Commission budget for 1965–1966.<ref>{{Cite news |title = $42&nbsp;Million County Road Fund OKd |date = October 30, 1964 |work = The San Diego Union |pages = A1–A2 |oclc = 13155544 }}</ref> A {{convert|6.7|mi|km|adj=on}} extension from Mountain Springs west to what was then known as Road J-35 was given $3.3&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|3300000|1965|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} in funding by the Highway Commission in May 1965.<ref>{{Cite news |title = $12&nbsp;Million Allocated for Work on Freeways |date = May 27, 1965 |work = Los Angeles Times |page = A2 |oclc = 3638237 }}</ref> The {{convert|10|mi|km|adj=on}} section in between this one and the Mountain Springs pass section was in planning by that September, and was scheduled to begin the building phase shortly thereafter, with the section extending west of Boulevard to follow.<ref>{{cite news |title = Bids To Be Sought For Building Freeway In Laguna Mountains |work = The San Diego Union |date = September 14, 1965 |page = A15 |oclc = 13155544 }}</ref> That section, from Crestwood to Boulevard, was to begin construction soon after the $3&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|3000000|1966|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} contract was given out in January 1966.<ref>{{Cite news |title = Contract Let For $3&nbsp;Million US&nbsp;80 Job |date = January 29, 1966 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref> The coming of the freeway from both west and east of Jacumba was projected to be a significant event in the history of the town.<ref name="jacumba"/> Cafes and gas stations went out of business once the freeway bypassed the town; however, many retirees relocated into the town since the high traffic levels were gone.<ref name="finally"/> The labeling of the town Boulevard as Manzanita on I-8 signs raised controversy and forced the Division of Highways to obscure the name on the signs until the issue was resolved.<ref>{{cite news |title = Community's Name Argument Resumes |work = Los Angeles Times |date = August 1, 1967 |author = Staff |page = A2 |oclc = 3638237 }}</ref>

Construction continued with the issuing of a $6.55&nbsp;million contract (about ${{Formatprice|{{Inflation|US-GDP|6550000|1967|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} to widen a {{convert|5.7|mi|km|adj=on}} section of I-8 through Alpine, from Harbison Canyon to east of West Victoria Drive, and to begin construction in April or May 1967, to be completed in 1969. This would leave only a {{convert|30|mi|km|adj=on}} stretch of I-8 that was not at freeway standards.<ref>{{Cite news |title = $6.5&nbsp;Million Road Job Let |date = April 18, 1967 |work = The San Diego Union |page = B3 |oclc = 13155544 }}</ref><ref>{{cite news |title = Contract Let for Segment of Freeway |work = Los Angeles Times |date = May 1, 1967 |author = Staff |page = 28 |oclc = 3638237 }}</ref> As the process continued, concerns about increased smog from the additional traffic were raised in October 1967.<ref>{{cite news |title = Smog Problem Eyed By El Cajon Council |work = The San Diego Union |date = October 20, 1967 |page = B3 |oclc = 13155544 }}</ref> A {{convert|3.7|mi|km|adj=on}} section to the east of Alpine was scheduled to have bidding opened in November of that year, and was to be finished in 1968; this would produce a continuous freeway from San Diego to the eastern terminus of this route.<ref>{{cite news |title = Bid Opening Set on Interstate 8 |work = Los Angeles Times |date = October 22, 1967 |author = Staff |page = 26 |oclc = 3638237 }}</ref> Both of these projects were underway by May 1968.<ref>{{cite news |title = Freeway Building Continues To Tie In County Cities |work = The San Diego Union |date = May 12, 1968 |page = B4 |oclc = 13155544 }}</ref> An additional contract was given out for $7.8&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|7800000|1968|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} in August to continue the freeway east from Alpine Street to Japatul Valley Road; this would bring the freeway near Descanso Junction.<ref>{{cite news |title = 3-Mile Interstate 8 Freeway Job Let |work = The San Diego Union |date = August 23, 1968 |page = B8 |oclc = 13155544 }}</ref> Roughly {{convert|5.5|e6cuyd|e6m3}} of dirt and rock were to be generated by all three of these construction projects, since half of a mountain would have to be removed with a million pounds of dynamite. The third project was built near the site of an abandoned attempt to build a tunnel for the old highway after World War II, which proved to be too expensive.<ref>{{Cite news |title = Million Points of Dynamite Slated to Clear Way for Interstate 8 Route |last = Hudson |first = Ken |date = September 8, 1968 |work = The San Diego Union |page = B2 |oclc = 13155544 }}</ref>

[[File:I-8 Alpine.jpg|thumb|right|I-8 in Alpine]]

By mid-February 1969, one segment of the freeway running through Alpine was nearing completion and was scheduled to open on February&nbsp;21; another section was scheduled to open in April. However, although dirt and rocks were transported on a conveyor belt across US&nbsp;80 to become part of an embankment for the [[Sweetwater River Bridge]], the grading of the mountain near Viejas Grade and the Sweetwater River had not been completed on the final link. The historic Ellis Grade radiator stop was to be removed and replaced with one at Vista Point.<ref>{{cite news |title = Interstate 8 Alpine Section Opens April 21 |work = The San Diego Union |date = February 12, 1969 |last = Hudson |first = Ken |page = B3 |oclc = 13155544 }}</ref> On April&nbsp;19, 1969, the part {{convert|2.5|mi|km|abbr=on}} east of Alpine opened to traffic.<ref>{{cite news |title = Freeway Link Opens At Alpine |work = The San Diego Union |date = April 20, 1969 |page = B2 |oclc = 13155544 }}</ref> All of the Alpine part of I-8 opened on May&nbsp;22, 1969, after a ribbon-cutting ceremony; yet the Viejas Grade segment was now projected to be completed by 1972.<ref name="alpinee">{{cite news |title = Interstate 8 Section Opened Near Alpine |work = The San Diego Union |date = May 23, 1969 |last = Hudson |first = Ken |page = B3 |oclc = 13155544 }}</ref> The bridge over the Sweetwater River was under construction by 1970,<ref>{{cite news |title = Mountain Freeway Link Progresses |work = The San Diego Union |date = January 25, 1970 |page = B3 |oclc = 13155544 }}</ref> and the entire segment cost $22.1&nbsp;million<ref name="bidformore">{{Cite news |title = County Freeways Dealt $47&nbsp;Million |date = April 24, 1970 |work = The San Diego Union |oclc = 13155544 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|22100000|1970|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} By May, this segment was estimated to be completed in the later part of that year.<ref name="fruition"/> The leveling of the grade resulted in the second highest fill in the state at {{convert|360|ft|m|abbr=on}}.<ref>{{cite news |title = Highway Group Gets Scenic Tour |work = The San Diego Union |date = May 26, 1970 |last = Stone |first = Joe |page = B1 |oclc = 13155544 }}</ref>

====Finishing the freeway====
The final portion of I-8 in California, between Japatul Valley Road and west of Boulevard, was prioritized in the 1969–1970 state budget.<ref>{{cite news |title = 18 Highway Projects Get Top Priority |work = The San Diego Union |date = March 19, 1968 |last = Clance |first = Homer |page = C1 |oclc = 13155544 }}</ref> Due to financial concerns, it was announced in September 1968 that the target date for completing the [[Interstate Highway System]] would be extended until 1974, from 1972. The missing portion of I-8 was expected to cost $45&nbsp;million and be constructed in three parts, with one part being started each year.<ref>{{cite news |title = Area's Freeways Losing Race With The Population |work = The San Diego Union |date = September 22, 1968 |page = B4 |oclc = 13155544 }}</ref> The segments between Japatul Valley Road and west of Laguna Junction, and from La Posta Road to west of Boulevard, were delayed for an entire year at the end of 1969 due to a nationwide effort to fight inflation by reducing spending.<ref>{{Cite news |title = $26.8&nbsp;Million Freeway Jobs OKd in County |date = October 22, 1969 |work = The San Diego Union |page = B3 |oclc = 13155544 }}</ref> A {{convert|6.6|mi|km|adj=on}} segment from Buckman Springs to Crestwood received funding in May 1970, which would leave only an {{convert|8|mi|km|adj=on}} stretch of the freeway uncompleted when built.<ref name="bidformore"/> The drive time from San Diego to El Centro had been reduced to two hours, according to the California Division of Highways.<ref name="fruition"/> By August 1970, the remainder of the freeway had been funded, with the part from Japatul Valley Road to Laguna Junction costing $22&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|22000000|1970|r=-6}}}} in {{inflation-year|US-GDP}} dollars),{{Inflation-fn|US-GDP}} and the Laguna Junction to Crestwood portion costing $15&nbsp;million<ref>{{Cite news |title = Area Freeway Work Costs $107.5&nbsp;Million |last = Clance |first = Homer |date = August 9, 1970 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|15000000|1970|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}}

In May 1971, El Centro Mayor Alex Gay requested that passing lanes be added to the remaining two-lane part of I-8 in between El Centro and San Diego due to the frequent traffic jams in between Japatul Valley and Crestwood. At this time, this was the only missing link through the mountains.<ref>{{cite news |title = Improving of Highway Link Sought |work = The San Diego Union |date = May 10, 1971 |author = Staff |page = B1 |oclc = 13155544 }}</ref> Bidding took place on the $16.5&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|16500000|1971|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} La Posta Road to Crestwood Road and the Japatul Valley Road to Sunrise Highway portions in November 1971.<ref>{{cite news |title = Interstate 8 Bids Called By State |work = The San Diego Union |date = November 26, 1971 |author = Staff |page = B3 |oclc = 13155544 }}</ref> As part of this series of projects, the highest concrete bridge in the state at the time was to be built at {{convert|430|ft|m|abbr=on}} over Pine Valley Creek on the segment between Japatul Valley Road and Sunrise Highway. The contract came in at $22.6&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|22600000|1972|r=-6}}}} in {{inflation-year|US-GDP}} dollars),{{Inflation-fn|US-GDP}} over $5&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|5000000|1972|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} beyond budget due to the difficulty of the bridge construction. All three of the projects to complete I-8 were projected to be complete by mid-1974.<ref>{{cite news |title = 430-Foot-High Bridge Planned For Route 8 |work = The San Diego Union |date = February 20, 1972 |last = Stewart |first = John |page = B3 |oclc = 13155544 }}</ref> However, in March 1972, it was announced that the La Posta Road portion of the project would be delayed due to budget troubles.<ref>{{Cite news |title = Money Problems Delay $150&nbsp;Million in Freeway Work |last = Kistler |first = Robert |date = March 29, 1972 |work = Los Angeles Times |page = A1 |oclc = 3638237 }}</ref>

By the beginning of 1974, the new projected completion date for I-8 was mid-1975, with {{convert|22|mi|km|abbr=on}} of two-lane highway remaining.<ref>{{cite news |title = Public's Mood Shifts Away From Freeways |work = The San Diego Union |date = January 8, 1974 |page = X16 |oclc = 13155544 }}</ref> The Pine Valley Creek bridge and the segment extending from Japatul Valley Road to Pine Valley was dedicated on November&nbsp;24, 1974, and was scheduled to open on November&nbsp;26; this left {{convert|8|mi|km|abbr=on}} of freeway to be constructed.<ref>{{cite news |title = Pine Valley Creek Bridge Dedicated |work = The San Diego Union |date = November 24, 1974 |pages = B1, B4 |oclc = 13155544 }}</ref> The final stretch of I-8 in California, from Sunrise Highway to La Posta Road, was completed in May 1975.<ref name="finally"/>

The Buckman Springs rest area opened in January 1979 in eastern San Diego County.<ref>{{cite news |title = San Diego |work = Los Angeles Times |date = January 18, 1979 |page = SD2 |oclc = 3638237 }}</ref> In 1987, the first {{convert|65|mph|km/h|abbr=on}} speed limit sign was posted east of El Cajon, the first one in the state; the speed limit on all I-8 east of El Cajon, except for the Mountain Springs Grade portion, was raised similarly.<ref>{{Cite news |title = 1st 65&nbsp;mph Sign Put Up East of El Cajon |last = Padilla, Steve |date = May 30, 1987 |work = The San Diego Union |page = B1 |oclc = 13155544 }}</ref>

===Imperial Valley===
====Construction====
[[File:IMPERIAL VALLEY. INTERSTATE HIGHWAY (I-8) SLICES THROUGH GREEN CROPLANDS - NARA - 549098.jpg|thumb|left|I-8 in the Imperial Valley, 1972]]
{{See also|U.S. Route 80 in California|Old Plank Road}}
The highway through Imperial Valley was originally a [[plank road]] made of pieces of wood that were tied together.<ref name="newroadlink">{{cite news |title = New Road Links San Diego, Yuma |work = Los Angeles Times |date = June 8, 1975 |last = Vance |first = Fred |page = G3 |oclc = 3638237 }}</ref> The Ocean-to-Ocean Bridge across the Colorado River was open in 1915.<ref name="yuma">{{cite news |title = Early Transportation Options Included Plank Road Over Sand Dunes |work = Yuma Sun |date = February 1, 2012 |author = Knaub, Mark }}</ref> Following this, US&nbsp;80 was built through the valley as the main east–west route.<ref>{{cite Caltrans map|year=1936}}</ref> Plans for a new freeway across the southernmost reaches of California date from before 1950.<ref name="plans">{{cite news |title = Completion of Freeway Link Nears |work = The San Diego Union |date = August 22, 1966 |page = B3 |oclc = 13155544 }}</ref> The bridge over the Colorado River was replaced in 1956, at a cost of $1.2&nbsp;million, and was in use until 1978, when the I-8 bridge was built.<ref name="bridgelink">{{cite news |title = Bridge Completes Last Link In Interstate 8 Job |work = The San Diego Union |date = August 19, 1978 |page = A3 }}</ref> In 1957, the City of El Centro expressed a desire for the new freeway to replace US&nbsp;80 to be routed along the southern limits of the city. Caltrans engineer Jacob Dekema stated at the time that the four-lane freeway would not be constructed on the US&nbsp;80 routing due to possible expansion of the [[Naval Air Facility El Centro]].<ref>{{Cite news |title = Highway&nbsp;80 Relocation Outlined |date = March 28, 1957 |work = Los Angeles Times |page = B8 |oclc = 3638237 }}</ref>

In October 1964, the portion of I-8 between Imperial Avenue in El Centro to SR&nbsp;111 appeared in the state budget.<ref>{{cite news |title = $42&nbsp;Million OKd for County Roads |work = The San Diego Union |date = October 30, 1964 |page = A2 |oclc = 13155544 }}</ref> By December, a route for the part of I-8 just west of the Colorado River was being examined by the California Highway Commission.<ref>{{cite news |title = Highway Group Studies New Route |work = The Yuma Sun |date = December 20, 1964 |page = 5 }}</ref> Construction was underway on the stretch from Seeley to SR&nbsp;111 by June 1966, and the entire portion through the county was planned for completion by 1968.<ref>{{cite news |title = High of 110 Predicted for Today |work = The San Diego Union |date = June 19, 1966 |page = A30 |oclc = 13155544 }}</ref> This {{convert|12.2|mi|km|adj=on}} portion, extending west to Drew Road, was planned for completion by early 1967, at a cost of $200&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|200000000|1967|r=-6}}}} in {{inflation-year|US-GDP}} dollars);{{Inflation-fn|US-GDP}} however, by then, the date for completion of the freeway had slipped to 1972.<ref name="plans"/> The state ordered the building of the portion from west of Coyote Wells to just east of Drew Road in September 1967.<ref>{{cite news |title = Rains Cause Flooding, Power Loss |work = The San Diego Union |date = September 2, 1967 |page = B3 |oclc = 13155544 }}</ref> The next year, Dekema indicated that the goal was to have I-8 completed by 1973, citing a deadline in order to have the federal government pay for up to ninety percent of the costs; the other freeways in the region were to be delayed because of this.<ref>{{Cite news |title = Freeway 8 to Yuma Seen by '73 |last = Hudson |first = Ken |date = April 5, 1968 |work = The San Diego Union |page = B3 |oclc = 13155544 }}</ref>

In early 1970, the portion of the freeway from west of Ogilby Road to east of Algodones Road was under construction, and projections were to have this portion completed by later that year. This $5.2&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|5200000|1970|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} project also included resurfacing the freeway that had already been built through the Colorado Desert Sandhills;<ref name="fruition"/> this part of the freeway had been built between 1961 and 1965.<ref>{{cite Caltrans map|year=1961}}</ref><ref>{{cite Caltrans map|year=1965}}</ref> By this time, it was estimated that the drive from San Diego to El Centro now took 2&nbsp;hours, as opposed to the 3.5&nbsp;hours required two decades earlier, and the two days required in the pioneer era.<ref name="fruition"/> This part of the freeway was opened in July 1970.<ref>{{cite news |title = Interstate 8 Link Ready |work = The San Diego Union |date = July 13, 1970 |page = B1 |oclc = 13155544 }}</ref><ref>{{Cite news |title = Interstate 8 Link Due by Next May |last = MacMillan |first = Doug |date = July 24, 1970 |work = The San Diego Union |edition = Imperial Valley |page = B1 |oclc = 13155544 }}</ref> As the freeway was constructed through the valley, it caused a break in many north–south roads. These breaks were located where access to the part of the road on the other side of the freeway was cut off. Plans were put in place to build [[frontage road]]s to improve access through the region.<ref>{{Cite news |title = 1,200&nbsp;Miles of County's Roads Paved |last = Ruane |first = Richard |date = February 21, 1971 |work = The San Diego Union |edition = Imperial Valley |page = B1 |oclc = 13155544 }}</ref>

The {{convert|16|mi|km|adj=on}} portion of I-8 bypassing [[Holtville, California|Holtville]] began construction in December&nbsp;1969, and was nearing completion in May 1971, to result in a continuous freeway that connected two existing segments from [[Crestwood, California|Crestwood]] in San Diego County to just west of Winterhaven. It was estimated that the bypass would save travelers 20&nbsp;minutes of travel time through the Imperial Valley. The cost of this project was $11.2&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|11200000|1969|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} However, Holtville residents raised concerns about SR&nbsp;115 providing the only access to the eastern part of the city,<ref>{{cite news |title = Final Work Being Done On Freeway |work = The San Diego Union |date = May 18, 1971 |author = Staff |page = B1 |edition = Imperial Valley |oclc = 13155544 }}</ref> notably the narrow and curved portion leading from the freeway into town. Work on the Holtville portion began at 3:30&nbsp;a.m. daily during the summer in order to avoid the desert heat. In addition to this, construction of the [[Highline Canal]] overpass involved a {{convert|120|ft|m|adj=on}} steel span that was prefabricated and made of girders that were hoisted into position by barges. The Matich Construction Company attempted to set the world record for laying the most concrete in a day, aided by the level terrain, but failed to do so after the [[concrete mixer]] malfunctioned.<ref>{{cite news |title = Interstate 8 Link To Open Near Holtville Next Month |work = The San Diego Union |date = April 29, 1971 |last = MacMillan |first = Doug |page = B1 |edition = Imperial Valley |oclc = 13155544 }}</ref> That same year, bids for an Arizona plant inspection station near Winterhaven, next to the California agricultural inspection station, were submitted.<ref>{{cite news |title = El Centro Firm's Bid Low For Inspection Station |work = The San Diego Union |date = September 18, 1970 |page = B1 |edition = Imperial Valley |oclc = 13155544 }}</ref>

The last {{convert|6.5|mi|km|adj=on}} part of the California portion, from near Algodones Road to west of the Arizona state line, was to enter the bidding phase in early 1972.<ref>{{cite news |title = Vegetable Shipments Up |work = The San Diego Union |date = December 15, 1971 |author = Staff |page = B1 |edition = Imperial Valley |oclc = 13155544 }}</ref> I-8 was scheduled to be completed in the summer of 1975 between San Diego and Yuma, although there would be a break in the freeway around Yuma;<ref name="newroadlink"/> this occurred by October 1975.<ref name="bridgelink"/> At the time the California portion was completed, it was the preferred route to Phoenix from some areas of Los Angeles, since [[Interstate 10 in Arizona|I-10]] had not been completed.<ref name="newroadlink"/>

The missing portion of the highway was the new bridge over the Colorado River, which was built at a cost of $7.4&nbsp;million<ref name="bridgelink"/> (about ${{Formatprice|{{Inflation|US-GDP|7400000|1975|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} In June 1975, there were concerns regarding the state delaying new construction projects due to financial concerns, and the effects this would have on the bridge.<ref>{{cite news |title = State Orders Halt In New Road Projects |work = The San Diego Union |date = June 19, 1975 |author = Staff |page = B1 |oclc = 13155544 }}</ref> The bid for the project was awarded to Novo-Rados Construction in October 1975, as one of the final projects before the construction freeze.<ref>{{Cite news |title = $14.9&nbsp;Million Road Project Awarded to Daley Corp. |date = October 4, 1975 |work = The San Diego Union |page = B5 |oclc = 13155544 }}</ref> The new bridge, which replaced the old US&nbsp;80 bridge, was dedicated on August&nbsp;18, 1978; this completed I-8 from San Diego to Casa Grande. The Arizona Department of Transportation and the City of Yuma assisted in the planning process. By the time the California portion of the freeway was complete, the average cost was $1&nbsp;million per mile<ref name="bridgelink"/> (about ${{Formatprice|{{Inflation|US-GDP|1000000|1978|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} The bridge opened on September&nbsp;20, 1978. The State of California was responsible for the bridge erection, even though the State of Arizona owned half of the bridge.<ref name="finish">{{cite news |title = Yuma I-8 Bridge Opens |work = The San Diego Union |date = September 21, 1978 |page = B4 |oclc = 13155544 }}</ref>

====Fratianno allegations====
[[Jimmy Fratianno]] was associated with [[Frank Bompensiero]], the San Diego mafia leader, in a criminal lawsuit involving the Fratianno Trucking Company and the Miles and Sons Trucking Company in 1966;<ref name=summary/> he was known to law enforcement as "the Mafia's West Coast executioner," with up to 16 deaths for which he was potentially responsible. Both companies were awarded the contracts to transport dirt during the construction of I-8 in El Centro. Drivers were coerced to agree to buy the trucks, although the Fratianno Company still retained the ownership; they also had portions of their wages withheld from them. Following this, the drivers were loaned money from Leo Moceri, another mafia leader.<ref name=summary/><ref name="convict"/> An investigation in early 1966 after complaints from the drivers led to state charges against the two firms as well as five people in August.<ref>{{cite news |title = Long-Burning Wage Dispute Flares Anew in Trucking Fraud Case |work = Los Angeles Times |date = August 26, 1966 |author = Houston, Paul |pages = A1, A3 |oclc = 3638237 }}</ref> There were concerns that John Erreca, the state director of public works, had a [[conflict of interest]] with Fratianno and did not enforce the law; however, both Transportation Administrator Robert Bradford (upon a request for investigation from then Governor [[Pat Brown]]) and the [[Federal Bureau of Investigation]] found that there was no conflict of interest.<ref>{{cite news |title = Report Clearing Erreca Just Whitewash, Accuser Charges |work = Los Angeles Times |date = October 12, 1966 |author = Staff |page = 3 |oclc = 3638237 }}</ref><ref>{{cite news |title = FBI Clears Erreca of Interest Conflict |work = Los Angeles Times |date = November 4, 1966 |page = A8 |oclc = 3638237 }}</ref>

The truck drivers were given $36,000 (about ${{Formatprice|{{Inflation|US-GDP|36000|1967|r=-3}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} in back pay from the state government.<ref>{{cite news |title = Truck Drivers to Get $36,000 in Back Pay |work = Los Angeles Times |date = December 10, 1967 |author = Brown, Nettie |page = B4 |oclc = 3638237 }}</ref> Fratianno and Bompensiero were charged with fraud, as well as state labor and public utility code violations. While charges were dropped against Bompensiero, Fratianno was found guilty.<ref name=summary/><ref name="convict">{{cite news |title = Ex-Convict Seized in Conspiracy Case |work = Los Angeles Times |date = August 18, 1966 |author = Houston, Paul |page = 3 |oclc = 3638237 }}</ref> The Imperial County [[board of supervisors|Board of Supervisors]] estimated that $25,000 (about ${{Formatprice|{{Inflation|US-GDP|25000|1893|r=-3}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} in damage to county roads took place due to overloaded trucks.<ref>{{cite news |title = Supervisors Get Advice on Road Damage Costs |work = Los Angeles Times |date = November 25, 1966 |author = Staff |page = 23 |oclc = 3638237 }}</ref> The federal government fined him $10,000 (about ${{Formatprice|{{Inflation|US-GDP|10000|1968|r=-3}}}} in {{inflation-year|US-GDP}} dollars),{{Inflation-fn|US-GDP}} which he never paid, and placed him on probation for three years; he was imprisoned when he did not pay, but was released in September 1969. His ex-wife, Jewell, as well as the company, were fined $4,014 (about ${{formatnum:{{Inflation|US-GDP|4014|1971|r=-3}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} individually for their responsibility in the matter.<ref>{{cite news |title = Court Orders Fratianno To Appear Here |work = The San Diego Union |date = July 11, 1971 |author = Himaka, Mitch |page = B1 |oclc = 13155544 }}</ref> For the state charges, he was sentenced in 1969 to one to three years in prison, after pleading guilty to the charges.<ref>{{cite news |title = Fratianno Gets Prison Term |work = The San Diego Union |date = January 12, 1969 |page = B7 |oclc = 13155544 }}</ref> He was incarcerated in [[Chico State Prison]] following a parole violation until 1973.<ref name="summary">{{Cite news |title = Bompensiero Move Into Top Mafia Post Here in 1960 |last = Clance, Homer |date = February 14, 1977 |work = The San Diego Union |pages = B1, B4 |oclc = 13155544 }}</ref>

====Storm damage====
Following [[Hurricane Kathleen (1976)|Tropical Storm Kathleen]] in September 1976, a flood eroded 400&nbsp;pieces of the roadway from westbound I-8 near [[Ocotillo, California|Ocotillo]], resulting in the construction of a detour. The freeway reopened to traffic in February 1978 after the damage was repaired and a new bridge was built, at a cost of $1&nbsp;million<ref>{{cite news |title = Imperial Riverside Counties Ruled Storm Disaster Areas |work = The San Diego Union |date = September 14, 1976 |author = Dillon, Patrick |page = A1 |oclc = 13155544 }}</ref><ref>{{cite news |title = Storm-Damaged Freeway Reopens |work = The San Diego Union |date = February 18, 1978 |page = B1 |oclc = 13155544 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|1000000|1978|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} But, in 1982, the freeway was closed again near Ocotillo due to flooding following another storm.<ref>{{Cite news |title = Rainstorm Floods and Blocks I-8 Near Ocotillo |last = Weber, Dick |date = December 10, 1982 |work = The San Diego Union |page = A1 |oclc = 13155544 }}</ref>

===Arizona===
{{see also|U.S. Route 80 in Arizona|Arizona State Route 84}}
[[File:Interstate 8 Eastern Terminus.jpg|thumb|right|I-10 approaching the eastern terminus of I-8]]
Between Yuma and Gila Bend, I-8 runs alongside the routes of both the [[Gila Trail]] and the [[Butterfield Overland Mail Company]] line. The latter was a [[stagecoach line]] that went between [[Tipton, Missouri]], and San Francisco, with several stations in between, and was used to transport passengers across the country at {{convert|5|mph|km/h|abbr=on}} between 1858 and 1861.<ref>{{harvp|Trimble|2004|pp=399–340}}.</ref> In later years, the [[Southern Pacific Railroad]] was constructed, paralleling the Gila River east of Fortuna;<ref>{{cite book |url = http://www.cr.nps.gov/history/online_books/geology/publications/bul/845/sec25.htm |title = Guidebook of the Western United States |publisher = Government Printing Office |author = Darton, D.H. |year = 1933 |location = Washington D.C. |archive-url = https://web.archive.org/web/20150203040904/http://www.cr.nps.gov/history/online_books/geology/publications/bul/845/sec25.htm |archive-date = February 3, 2015 }}</ref> by 1877, the tracks were complete to Yuma. Work continued the next year, and, by 1880, the tracks were extended to Tucson from Yuma.<ref>{{cite book |url = http://www.cprr.org/Museum/SP_1869-1944/ |title = Seventy-Five Years of Progress |publisher = Southern Pacific Bureau of News |author = Heath, Erle |year = 1945 |location = San Francisco |access-date = July 17, 2014 |archive-url = https://web.archive.org/web/20140502033002/http://www.cprr.org/Museum/SP_1869-1944/ |archive-date = May 2, 2014 |url-status = live }}</ref>

This portion of the route of US&nbsp;80, predecessor of I-8, was originally part of the proposed state system of highways in 1921.<ref name="1921 map">{{cite map |author = Arizona Highway Department |location = Phoenix |publisher = Arizona Highway Department |url = http://www.aaroads.com/west/maps/1921-az.jpg |title = Tentative 7% System |year = 1921 |access-date = December 14, 2016 |archive-url = https://web.archive.org/web/20160319100204/http://www.aaroads.com/west/maps/1921-az.jpg |archive-date = March 19, 2016 |url-status = live }}</ref> By 1926, this section became part of the cross-country highway [[U.S. Route 80 in Arizona|US&nbsp;80]]. The route was not paved at this time, but was a gravel road along the entire corridor.<ref name="1926 map">{{cite map |author = Arizona Highway Department |location = Phoenix |url = http://www.aaroads.com/west/maps/1926-az.jpg |title = Map of Arizona |year = 1926 |publisher = Arizona Highway Department |access-date = December 14, 2016 |archive-url = https://web.archive.org/web/20160304074648/http://www.aaroads.com/west/maps/1926-az.jpg |archive-date = March 4, 2016 |url-status = live }}</ref> By 1928, the portion of I-8 between Gila Bend and Casa Grande was designated as SR&nbsp;84.<ref>{{cite web |date = February 7, 1928 |author = Arizona Department of Transportation |publisher = Arizona Department of Transportation |access-date = May 4, 2008 |url = http://www.azhighwaydata.com/resolutions/?resnum=1928-P-144 |title = Resolution 1928-P-144 |work = Right-of-Way Resolutions |archive-url = https://web.archive.org/web/20110904202420/http://www.azhighwaydata.com/resolutions/?resnum=1928-P-144 |archive-date = September 4, 2011 |url-status = live }}</ref> A small portion of the highway was paved near Yuma and SR&nbsp;84 was under construction by the next year.<ref name="1929 map">{{cite map |author = Arizona Highway Department |location = Phoenix |publisher = Arizona Highway Department |url = http://www.aaroads.com/west/maps/1929-az.jpg |title = Map of Arizona |year = 1929 |access-date = December 14, 2016 |archive-url = https://web.archive.org/web/20160326175224/http://www.aaroads.com/west/maps/1929-az.jpg |archive-date = March 26, 2016 |url-status = live }}</ref> SR&nbsp;84 was completed by 1930, but not paved, and the segment of US&nbsp;80 between [[Aztec, Arizona|Aztec]] and [[Sentinel, Arizona|Sentinel]] had been paved.<ref name="1930 map">{{cite map |author = Arizona Highway Department |location = Phoenix |publisher = Arizona Highway Department |url = http://www.aaroads.com/west/maps/1930-az.jpg |title = Condition Map of State Highway System |year = 1930 |access-date = December 14, 2016 |archive-url = https://web.archive.org/web/20160319022611/http://www.aaroads.com/west/maps/1930-az.jpg |archive-date = March 19, 2016 |url-status = live }}</ref>

Paving of SR&nbsp;84 had commenced by 1934, with the portion of the highway in Maricopa County being paved.<ref name="1934 map">{{cite map |author = Arizona Highway Department |location = Phoenix |url = http://www.aaroads.com/west/maps/1934-az.jpg |title = Condition Map of State Highway System |year = 1934 |publisher = Arizona Highway Department |access-date = May 4, 2008 |archive-url = https://web.archive.org/web/20160314145514/http://www.aaroads.com/west/maps/1934-az.jpg |archive-date = March 14, 2016 |url-status = live }}</ref> A group of San Diego citizens raised concerns about the road from Yuma to Gila Bend not being paved in 1934, due to the impact that this would have on tourism in San Diego, and made a request to the federal government to have it paved.<ref>{{Cite news |title = SD Aid Sought to Win Funds for Improving Route to City |date = April 1, 1934 |work = The San Diego Union |edition = Imperial Valley |page = A1 |oclc = 13155544 }}</ref> The entire future corridor of I-8 had been paved from Yuma to Casa Grande by 1935.<ref name="1935 map">{{cite map |url = http://www.arizonaroads.com/maps/index.html |title = Road Map of Arizona |year = 1935 |publisher = Arizona Highway Department |first = H.M. |last = DeMerse |location = Phoenix |access-date = May 4, 2008 |archive-url = https://web.archive.org/web/20080506234706/http://www.arizonaroads.com/maps/index.html |archive-date = May 6, 2008 |url-status = live }}</ref> Drivers were told to bring spare fan belts, radiator hoses, and additional drinking water for the journey traversing the desert.<ref>{{harvp|Trimble|2004|p=154}}.</ref> A "Shortcuts Association" began in 1952 to promote SR&nbsp;84 as a route to bypass Phoenix on the way to San Diego.<ref>{{Cite news |title = Group to Mark SD Shortcuts |date = August 26, 1952 |work = The San Diego Union |page = A6 |oclc = 13155544 }}</ref>

With the coming of the Interstate Highways, the corridor was to be upgraded to Interstate standards. In late 1958, a group of motel owners whose properties were located on SR&nbsp;84 strongly objected to any routing of I-8 that would not go through the city of Casa Grande.<ref>{{cite news |title = Motel Men Seem to Prefer Fenced-Off Road Through City |work = Casa Grande Dispatch |date = November 20, 1958 |author = Mauntz, Ted |page = 1 |oclc = 16877473 }}</ref> Motel owners in Yuma proposed their own alternative in 1961 to the four routings of I-8 through the city that had been proposed, raising concerns about losing revenue from tourism.<ref>{{cite news |title = Yuma Motel Owners Urge Different Route |work = The Yuma Daily Sun |date = December 3, 1961 |page = 16 |oclc = 11279925 }}</ref> In January 1962, the alternatives were narrowed down to two, with one of them being the route supported by the motel owners. However, nearby school officials expressed concerns regarding that route, because 1200&nbsp;students would no longer be able to walk to school if the freeway was constructed along that route.<ref>{{cite news |title = Interstate 8 Appears Set for One of Two Routes |work = The Yuma Daily Sun |date = January 4, 1962 |page = 1 |oclc = 11279925 }}</ref> Later that year, a new route had been proposed, along the Southern Pacific Railroad tracks and the Colorado River.<ref>{{cite news |title = Highway Dept. Plans Traffic Study Here |work = The Yuma Daily Sun |date = September 5, 1962 |page = 1 |oclc = 11279925 }}</ref> Construction was completed on the first sections of I-8 in Arizona in 1958. The first section was {{convert|1.33|mi|km|0|abbr=off}} long, which included a grade-separated interchange south of the [[Painted Rock Petroglyph Site]]. The second section, which was {{convert|0.83|mi|km|abbr=off}} in length, also included a grade separated interchange at [[Aztec, Arizona|Aztec]], just east of [[Dateland, Arizona|Dateland]]. The interchange at [[Sentinel, Arizona|Sentinel]], and the section between Aztec and the [[Maricopa County, Arizona|Maricopa County]] line, which included the construction of another interchange, were both completed in 1959.<ref>{{ADOT log|year=1965|access-date=June 27, 2023}}</ref> The initial construction was divided into four different sections awarded to different contractors. Work commenced with a section of US&nbsp;80 between [[Sentinel, Arizona|Sentinel]] and Gila Bend on December&nbsp;10, 1960. This was also the section of I-8 completed in Arizona on April 18, 1962.<ref name="AZRepublic1962">{{Cite news |url = https://www.newspapers.com/clip/32739020/state_road_jobs_eyed_by_house/ |title = State Road Jobs Eyed by House |last = Cole |first = Ben |date = May 1, 1963 |work = Arizona Republic |access-date = June 10, 2019 |location = Phoenix |pages = 1, [https://www.newspapers.com/clip/32739065/state_road_jobs_eyed_by_house_part_2/ 4] |via = Newspapers.com |archive-url = https://web.archive.org/web/20190826224403/https://www.newspapers.com/clip/32739020/state_road_jobs_eyed_by_house/ |archive-date = August 26, 2019 |url-status = live }}</ref> By 1963, work was well under way, with portions of US&nbsp;80 between [[Mohawk, Arizona|Mohawk]] and Gila Bend, and SR&nbsp;84 between Gila Bend and near Stanfield upgraded.<ref name="1963 map">{{cite map |url = http://www.aaroads.com/west/maps/1963-az.html |title = Road Map of Arizona |year = 1963 |publisher = Arizona Highway Department |author1 = Arizona Highway Department |author2 = Rand McNally |scale = 1&nbsp;in:24&nbsp;mi |access-date = May 4, 2008 |archive-url = https://web.archive.org/web/20110621235009/http://www.aaroads.com/west/maps/1963-az.html |archive-date = June 21, 2011 |url-status = live }}</ref> Other merchants objected to the routing, and met with the Yuma County Board of Supervisors to raise their concerns following the final approval of the route in 1964.<ref>{{cite news |title = Yuma Mesa Merchants Protest to County About Bypass |work = The Arizona Republic |date = January 10, 1964 |author = Grounds, Lucy |location = Phoenix |page = 17 |oclc = 2609778 }}</ref> A new park was to be built east of the Colorado River crossing, just opposite downtown; city officials hoped that this would give an improved look to the town as drivers first arrived.<ref>{{cite news |title = Shrewd Planning Used to Revitalize Yuma |work = The Arizona Republic |date = July 3, 1966 |page = A17 |oclc = 2609778 }}</ref>

Nevertheless, there was controversy over the work in Arizona as well. In 1964, a [[U.S. House of Representatives]] investigation discovered that poor management and lack of efficiency were prevalent in four of the projects constructing the I-8 freeway. The Arizona Highway Department was specifically cited in the report for not taking into account protecting government interests when selecting labor for the projects. Several errors were discovered, and one of them, adding too much clay to the gravel mixture, cost the state of Arizona $26,278 (about ${{Formatprice|{{Inflation|US-GDP|26278|1963|r=-3}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} to fix.<ref>{{Cite news |title = Officials Claim Shock at Road Test Fakes |last = Cole, Ben |date = May 8, 1963 |work = The Arizona Republic |location = Phoenix |page = 1 |oclc = 2609778 }}</ref><ref>{{cite news |title = House Unit Lambastes Arizona Road Building |work = Los Angeles Times |date = June 20, 1964 |page = 8 |oclc = 3638237 }}</ref> By that year, construction had begun on the freeway west of Casa Grande, while the rest of the Arizona routing was in the design stages.<ref>{{cite news |title = Arizonans May Use Freeways Long Before Interstate System Complete |work = The Arizona Republic |date = June 28, 1964 |page = 16A |oclc = 2609778 }}</ref>

In 1965, a $1.46&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|1460000|1965|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} contract was granted to build the {{convert|5.7|mi|km|adj=on}} portion from near Araby Road east through Fortuna Wash.<ref>{{cite news |title = $1.5 Million Interstate 8 Job Let For 5.7 Miles near Araby Road |work = The Yuma Daily Sun |date = January 16, 1966 |oclc = 112799251 }}</ref> Two years later, it was estimated that construction would be complete by 1969, except for the Colorado River bridge. The highway was in progress through the Telegraph Pass east of Yuma, and the portions from Avenue 9-E to 4-E, from there to 4th&nbsp;Street in Yuma, and to the river were estimated to cost $9.69&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|9690000|1967|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} in total.<ref>{{cite news |title = Yuma Will Have I-8 Freeway by 1969 |work = The Yuma Daily Sun |date = February 23, 1967 |page = 6 |oclc = 11279925 }}</ref> Following local complaints, Francis Turner, the executive director of the federal [[Bureau of Public Roads]], agreed to look at constructing an interchange at Trekell Road in Casa Grande again, after an earlier decline to do so.<ref>{{Cite news |title = Highway Chief Promises to Reconsider Access |date = June 4, 1967 |work = Casa Grande Dispatch |page = 1 |oclc = 16877473 }}</ref> Work began on the Casa Grande part of the freeway in March 1968, at a cost of $3&nbsp;million<ref name="trafficstart"/> (about ${{Formatprice|{{Inflation|US-GDP|3000000|1968|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} That year, many gas station, motel, and restaurant owners noticed a drop in business, possibly due to concerns regarding construction traffic due to I-8; however, they hoped for increased business following completion of the freeway.<ref>{{Cite news |title = Yuma Motel People Know about Hwy.&nbsp;80 Traffic Drop |last = O'Neill, Don |date = August 18, 1968 |work = The Yuma Daily Sun |page = 3 |oclc = 11279925 }}</ref> The Yuma County Chamber of Commerce made plans to promote tourism in the town following the completion of I-8 by late 1968.<ref>{{cite news |title = Yuma Chamber Plans To Gather Tourists from Interstate 8 Bypass |work = The Yuma Daily Sun |date = December 4, 1968 |page = 1 |oclc = 11279925 }}</ref>

Bidding on the last portion of the freeway to be completed in Casa Grande, from Midway Road to I-10, was to begin in January 1969.<ref>{{cite news |title = Bids To Be Called For Final I-8 Link |work = Casa Grande Dispatch |date = January 20, 1969 |page = 1 |oclc = 16877473 }}</ref> By November, the freeway east of Yuma was under construction, at a cost of $3.7&nbsp;million<ref>{{Cite news |title = Yuma Construction Totals $12&nbsp;Million |date = November 23, 1969 |work = The Yuma Daily Sun |page = 5 |oclc = 11279925 }}</ref> (about ${{Formatprice|{{Inflation|US-GDP|3700000|1969|r=-6}}}} in {{inflation-year|US-GDP}} dollars).{{Inflation-fn|US-GDP}} On June&nbsp;15, 1970, eastbound traffic began on I-8 in Casa Grande, with an exit at both Trekell and Thorton roads, with westbound traffic soon to follow.<ref name="trafficstart">{{Cite news |title = Traffic Starts Today on I-8 Eastbound Lane |date = June 15, 1970 |work = Casa Grande Dispatch |page = 1 |oclc = 16877473 }}</ref> Businesses did not notice much change with the opening of the eastbound lanes.<ref>{{Cite news |title = Businessmen Have Mixed Views on Opening of Interstate 8 |last = Kramer, Donovan Jr. |date = June 17, 1970 |work = Casa Grande Dispatch |page = 1 |oclc = 16877473 }}</ref> In 1971, I-8 was nearly complete, including a new alignment east of Yuma built parallel and to the south of the original US&nbsp;80 alignment. A new alignment was also built to the south of the SR&nbsp;84 alignment at the eastern end of the highway from southwest of Stanfield to the eastern terminus at I‑10 southeast of Casa Grande. The only portions of I-8 not completed at this time were the Gila Bend bypass and the western end near Yuma.<ref name="1971 map">{{cite map |url = http://www.aaroads.com/west/maps/1971-az.html |title = Road Map of Arizona |year = 1971 |publisher = Arizona Highway Department |author = Arizona Highway Department Photogrammetry and Mapping Division |location = Phoenix |access-date = May 4, 2008 |archive-url = https://web.archive.org/web/20110621235036/http://www.aaroads.com/west/maps/1971-az.html |archive-date = June 21, 2011 |url-status = live }}</ref> The portion east of 16th&nbsp;Street in Yuma was completed in June 1972;<ref>{{cite news |title = Interstate 8 Section Opens Wednesday at 10 |work = The Yuma Daily Sun |date = June 6, 1972 |page = 1 |oclc = 15337492 }}</ref> the Arizona State Highway Commission authorized the $1.6&nbsp;million (about ${{Formatprice|{{Inflation|US-GDP|1600000|1962|r=-6}}}} in {{inflation-year|US-GDP}} dollars){{Inflation-fn|US-GDP}} contract to construct the {{convert|6|mi|km|adj=on}} portion through Gila Bend in August.<ref>{{Cite news |title = Gila Bend I-8 Link Gets OK |date = August 26, 1972 |work = Tucson Daily Citizen |page = 6 |oclc = 15304868 }}</ref> Some Yuma businesses had noticed a decrease in revenue at this time; the Arizona Highway Department agreed to modify some signs to eliminate any confusion.<ref>{{cite news |title = 11 Major Sign Changes Promised on Interstate 8 |work = The Yuma Daily Sun |date = June 27, 1972 |author = Staff |page = 1 |oclc = 15337492 }}</ref> The part of I-8 between 16th and 4th&nbsp;streets was under construction in 1976, which was the only incomplete part of the freeway, along with the bridge over the Colorado River. The water treatment plant in Yuma was to be moved due to the potential of an accident with a vehicle carrying hazardous materials flying off the bridge and contaminating the water supply.<ref>{{cite news |title = I-8 Bridge and Water Works Are on Collision Course Here |work = The Yuma Daily Sun |date = October 2, 1970 |author = Battin, John |page = 1 |oclc = 15337492 }}</ref><ref>{{cite news |title = Downtown Busy With Construction |work = The Yuma Daily Sun |date = January 1, 1976 |author = Bush, Ernie |page = 14 |oclc = 15337492 }}</ref> The freeway in both states was completed with the opening of the bridge on September&nbsp;20, 1978.<ref name="finish"/>

As the Interstate was completed, the highways that it replaced were removed from the state highway system. In 1973, the SR&nbsp;84 designation was removed from the highway from Gila Bend to the split where I-8 followed a new alignment southwest of Stanfield.<ref>{{cite web |date = September 21, 1973 |publisher = Arizona Department of Transportation |access-date = May 4, 2008 |url = http://www.azhighwaydata.com/resolutions/?resnum=1973-%20-075 |title = Resolution 1973-20-075 |author = Arizona Department of Transportation |work = Right-of-Way Resolutions |archive-url = https://web.archive.org/web/20120316141609/http://www.azhighwaydata.com/resolutions/?resnum=1973-%20-075 |archive-date = March 16, 2012 |url-status = live }}</ref> In 1977, the US&nbsp;80 designation was removed from this stretch in favor of I-8.<ref>{{cite web |date = September 16, 1977 |publisher = Arizona Department of Transportation |access-date = May 4, 2008 |url = http://www.azhighwaydata.com/resolutions/?resnum=1977-16-A-048 |title = Resolution 1977-16-A-048 |author = Arizona Department of Transportation |work = Right-of-Way Resolutions |archive-url = https://web.archive.org/web/20110915101608/http://www.azhighwaydata.com/resolutions/?resnum=1977-16-A-048 |archive-date = September 15, 2011 |url-status = live }}</ref>

==Exit list==
{{jcttop|exit|state_col=state|length_ref=<ref name=calnexus/><ref name="ADOT Highway Log">{{ADOT log|year=2013|access-date=October 15, 2019|pages=1–11|location=on}}</ref>
|exit_ref=<ref name=calnexus>{{cite web |publisher = California Department of Transportation |work = California Numbered Exit Uniform System |url = http://www.dot.ca.gov/trafficops/exit/docs/8.pdf |title = Interstate 8 Freeway Interchanges |access-date = February 5, 2009 |author = Warring, KS |date = January 9, 2008 |location = Sacramento |archive-url = https://web.archive.org/web/20160820173904/http://www.dot.ca.gov/trafficops/exit/docs/8.pdf |archive-date = August 20, 2016 |url-status = live }}</ref>
<!--|notes_ref=<ref>{{cite web |url = https://preservetucson.org/wp-content/uploads/2017/09/Arizona-Historic-US-Route-80-Applicaiton-Submitted-to-ADOT-July-2016-small-file-for-web2.pdf |title = Historic Arizona U.S. Route 80 Historic Highway Designation Application |publisher = Tucson Historic Preservation Foundation |work = Application Document |date = May 2016 |access-date = August 24, 2018 |author = Clinco, Demion |pages = 251 }}</ref><ref>{{cite map |url = http://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~212030~5500188:Shell-Highway-Map-of-Arizona-?sort=Date&qvq=w4s:/what/Automobile/where/Arizona;q:Arizona;sort:Date;lc:RUMSEY~8~1&mi=10&trs=12 |title = Shell Highway Map of Arizona |year = 1956 |author2 = H.M. Gousha Company |author1 = Shell Oil Company |location = Chicago |publisher = Shell Oil Company |scale = 1:1,330,560 |via = David Rumsey Map Collection |access-date = March 31, 2015 }}</ref>--><!--unless these two items apply to the whole notes column, they shouldn't be here. rather, they should probably be tagged onto the specific notes they support.-->}}
{{CAint|exit
|sspan=71
|county=San Diego
|cspan=46
|location=San Diego
|lspan=16
|mile=0.00
|exit=
|road=Nimitz Boulevard / Sunset Cliffs Boulevard&nbsp;– [[Mission Bay Park]]
|notes=[[At-grade intersection]]
}}
{{CAint|exit
|type=incomplete
|mile=0.50
|exit=1
|road=West Mission Bay Drive / Sports Arena Boulevard
|notes=Westbound exit and eastbound entrance}}
{{CAint|exit
|type=incomplete
|mile=1.67
|mspan=3
|exit=2A
|road={{Jct|state=CA|I|5|dir1=north|city1=Los Angeles}}
|notes=Westbound exit and eastbound entrance; I-5 south exit 20; former [[U.S. Route 101 in California#Historic route: San Diego to Los Angeles|US 101]] north}}
{{CAint|exit
|type=incomplete
|exit=2B
|espan=2
|mile=none
|road=Rosecrans Street
|notes=Westbound exit and eastbound entrance; former [[California State Route 209|SR&nbsp;209]] south}}
{{CAint
|mile=none
|exit=2B
|road={{Jct|state=CA|I|5|dir1=south|location1=[[Downtown San Diego|Downtown]]}}
|notes=Signed as exit 2 eastbound; I-5 north exit 20; former [[U.S. Route 101 in California#Historic route: San Diego to Los Angeles|US 101]] south
}}
{{CAint|exit
|type=incomplete
|mile=2.03
|exit=2C
|road=Morena Boulevard
|notes=No eastbound exit}}
{{CAint|exit
|mile=2.60
|exit=3
|road=Taylor Street / Hotel Circle
|notes=}}
{{CAint|exit
|mile=3.88
|exit=4A
|type=incomplete
|road=Hotel Circle
|notes=Westbound exit is via exit&nbsp;3}}
{{CAint|exit
|mile=4.06
|exit=4B–C
|road={{Jct|state=CA|CA|163|location1=[[Downtown San Diego|Downtown]]|city2=Escondido}}
|notes=Signed as exits 4B (south) and 4C (north) eastbound and as exits 4A (south) and 4B (north) westbound; SR 163 exits 3A-B; former [[U.S. Route 395 in California#Current designation|US 395]]}}
{{CAint|exit
|mile=4.69
|exit=5
|road=Mission Center Road / Auto Circle
}}
{{CAint|exit
|mile=5.55
|exit=6A
|road=Texas Street / Qualcomm Way
|notes=Qualcomm Way was formerly Stadium Way<ref>{{Cite web |date = April 9, 1997 |title = San Diego Stadium Name Change Finalized for Qualcomm |url = https://www.sportsbusinessjournal.com/Daily/Issues/1997/04/09/Facilities-Venues/SAN-DIEGO-STADIUM-NAME-CHANGE-FINALIZED-FOR-QUALCOMM.aspx |access-date = March 26, 2023 |work = Sports Business Journal |language = en-US }}</ref>
}}
{{CAint|exit
|mile=6.03
|exit=6B
|road={{Jct|state=CA|I|805|city1=Los Angeles|city2=National City|city3=Chula Vista}}
|notes=I-805 north exit 17; south exit 17B}}
{{CAint|exit
|mile=7.29
|mile2=7.31
|exit=7
|road={{Jct|state=CA|I|15|dir1=north|city1=Riverside}}<br>{{Jct|state=CA|SR|15|dir1=south}}
|notes=Signed as exits 7A (south) and 7B (north) westbound; I-15 south / SR 15 north exit 6B; former [[California State Route 103#History|SR 103]]
}}
{{CAint|exit
|mile=7.94
|exit=8
|road=Mission Gorge Road / Fairmount Avenue
|notes=Eastbound exit is part of exit&nbsp;7}}
{{CAint|exit
|mile=8.71
|exit=9
|road=Waring Road
}}
{{CAint|exit
|mile=9.99
|exit=10
|road=College Avenue
|notes=Serves [[San Diego State University]]}}
{{CAint|exit
|location=La Mesa
|lspan=8
|mile=11.24
|exit=11
|road=Lake Murray Boulevard / 70th Street
|notes=}}
{{CAint|exit
|mile=12.22
|exit=12
|road=Fletcher Parkway / Baltimore Drive
|notes=Baltimore Drive not signed eastbound}}
{{CAint|exit
|type=incomplete
|mile=12.62
|exit=13A
|espan=2
|road=Spring Street&nbsp;– [[Downtown La Mesa, California|Downtown La Mesa]]
|notes=No westbound exit}}
{{CAint
|type=incomplete
|mile=12.75
|road=[[El Cajon Boulevard]]
|notes=Westbound exit and eastbound entrance; former [[Interstate 8 Business (San Diego, California)|I-8 Bus.]] and [[U.S. Route 80 in California|US&nbsp;80]] west}}
{{CAint|exit
|type=incomplete
|mile=13.41
|exit=13B
|road=Jackson Drive / Grossmont Boulevard
|notes=No eastbound entrance; no westbound signage for Grossmont Boulevard}}
{{CAint|exit
|mile=14.05
|exit=14A
|road=La Mesa Boulevard / Grossmont Center Drive
|notes=Signed as exit&nbsp;14B eastbound}}
{{CAint|exit
|mile=14.20
|exit=14B
|road={{Jct|state=CA|SR|125}}
|notes=Signed as exit 14A&nbsp;eastbound; exit 18A on SR 125; formerly [[California State Route 67#Early days|SR 67]] south of I-8}}
{{CAint|exit
|mile=14.30
|exit=14C
|road=Severin Drive / Fuerte Drive
|notes=}}
{{CAint|exit
|location=El Cajon
|lspan=8
|type=incomplete
|mile=15.31
|exit=15
|road=[[El Cajon Boulevard]] ([[Interstate 8 Business (El Cajon, California)|I-8 Bus.]] east)
|notes=Eastbound exit and westbound entrance; former [[U.S. Route 80 in California|US&nbsp;80]] east}}
{{CAint|exit
|mile=16.24
|exit=16
|road=Main Street
|notes=}}
{{CAint|exit
|type=incomplete
|mile=16.95
|exit=17A
|road=Johnson Avenue
|notes=Eastbound exit and westbound entrance}}
{{CAint|exit
|mile=17.45
|exit={{nowrap|17B–C}}
|road={{Jct|state=CA|SR|67|dir1=north|road|Magnolia Avenue|city1=Santee|city2=Lakeside|city3=Ramona}}
|notes=Signed as exits&nbsp;17B (SR&nbsp;67) and 17C (Magnolia Avenue) eastbound; SR&nbsp;67 exit&nbsp;1}}
{{CAint|exit
|mile=18.12
|exit=18
|road=Mollison Avenue
|notes=}}
{{CAint|exit
|mile=19.01
|exit=19
|road=2nd Street ([[California State Route 54 Business (El Cajon)|SR 54 Bus.]] west)
|notes=Former [[California State Route 54|SR&nbsp;54]] west}}
{{CAint|exit
|type=incomplete
|mile=19.50
|exit=20A
|road=East Main Street ([[Interstate 8 Business (El Cajon, California)|I-8 Bus.]] west)
|notes=Westbound exit and eastbound entrance}}
{{CAint|exit
|mile=20.40
|exit=20B
|road=Greenfield Drive&nbsp;– [[Crest, California|Crest]]
|notes=Signed as exit&nbsp;20 eastbound}}
{{CAint|exit
|location=Lakeside
|lspan=2
|mile=21.69
|exit=22
|road=Los Coches Road&nbsp;– [[Lakeside, California|Lakeside]]
|notes=}}
{{CAint|exit
|mile=23.47
|exit=23
|road=Lake Jennings Park Road
|notes=}}
{{CAint|exit
|location=none
|mile=27.34
|exit=27
|road=Dunbar Lane&nbsp;– [[Harbison Canyon, California|Harbison Canyon]]
|notes=}}
{{CAint|exit
|location=Alpine
|lspan=2
|mile=30.11
|exit=30
|road=Tavern Road ([[Interstate 8 Business (Alpine, California)|I-8 Bus.]] east)&nbsp;– [[Alpine, California|Alpine]]
|notes=}}
{{CAint|exit
|mile=32.99
|exit=33
|road=Willows Road / Alpine Boulevard ([[Interstate 8 Business (Alpine, California)|I-8 Bus.]] west)&nbsp;– [[Alpine, California|Alpine]]
|notes=Serves [[Viejas Group of Capitan Grande Band of Mission Indians|Viejas Reservation]]}}
{{CAint|exit
|location=none
|mile=35.98
|exit=36
|road=East Willows Road
|notes=Former US 80}}
{{CAint|exit
|location=none
|mile=39.48
|exit=40
|road={{Jct|state=CA|SR|79|dir1=north|name1=Japatul Valley Road|city1=Descanso|city2=Julian}}
|notes=Serves [[Viejas Group of Capitan Grande Band of Mission Indians|Viejas Reservation]]}}
{{CAint|exit
|location=Pine Valley
|lspan=2
|mile=45.18
|exit=45
|road=[[Pine Valley, California|Pine Valley]], [[Julian, California|Julian]]
|notes=}}
{{CAint|exit
|mile=46.58
|exit=47
|road=Sunrise Highway ([[County Route S1 (California)|CR S1]])
|notes=}}
{{CAint|exit
|location=none
|mile=50.49
|exit=51
|road=Buckman Springs Road
|notes=}}
{{CAint|exit
|location=none
|mile=53.63
|exit=54
|road=Kitchen Creek Road&nbsp;– [[Cameron Station, California|Cameron Station]]
|notes=}}
{{CAint|exit
|location=Campo Indian Reservation
|mile=60.50
|exit=61
|road=Crestwood Road&nbsp;– [[Live Oak Springs, California|Live Oak Springs]]
|notes=Serves [[Campo Indian Reservation]], [[La Posta Band of Diegueño Mission Indians|La Posta Reservation]], [[Manzanita Band of Diegueno Mission Indians|Manzanita Indian Reservation]]}}
{{CAint|exit
|location=none
|mile=65.25
|exit=65
|road={{Jct|state=CA|SR|94|dir1=west|city1=Campo|city2=Boulevard}}
|notes=}}
{{CAint|exit
|location=none
|mile=73.30
|exit=73
|road=[[Jacumba, California|Jacumba]]
|notes=}}
{{CAint|exit
|county1=San Diego
|county2=Imperial
|location=none
|mile=76.93
|exit=77
|road=In-Ko-Pah Park Road
|notes=}}
{{CAint|exit
|county=Imperial
|cspan=24
|location=none
|mile=80.21
|exit=80
|road=Mountain Springs Road
|notes=}}
{{CAint|exit
|location=none
|type=incomplete
|mile=87.13
|exit=87
|road={{Jct|state=CA|SR|98|dir1=east|city1=Calexico}}
|notes=Eastbound exit and westbound entrance}}
{{CAint|exit
|location=Ocotillo
|mile=89.04
|exit=89
|road=[[Imperial Highway]] ([[County Route S2 (California)|CR&nbsp;S2]])&nbsp;– [[Ocotillo, California|Ocotillo]]
|notes= Former U.S. Route 80 east}}
{{CAint|exit
|location=none
|mile=100.60
|exit=101
|road=Dunaway Road
|notes=}}
{{CAint|exit
|location=none
|mile=107.05
|exit=107
|road=Drew Road ([[County Route S29 (California)|CR&nbsp;S29]])&nbsp;– [[Seeley, California|Seeley]]
|notes=}}
{{CAint|exit
|location=none
|mile=111.11
|exit=111
|road=Forrester Road ([[County Route S30 (California)|CR&nbsp;S30]])
|notes=}}
{{CAint|exit
|location=El Centro
|lspan=3
|mile=114.09
|exit=114
|road=Imperial Avenue ([[Interstate 8 Business (El Centro, California)|I-8 Bus.]] east)&nbsp;– [[El Centro, California|El Centro]]
|notes=<!-- Exit was reconsructed from April 2020 to December 2021 which included a long-term closure https://kyma.com/news/top-stories/2021/12/23/1-8-imperial-avenue-interchange-officially-open-->}}
{{CAint|exit
|mile=115.09
|exit=115
|road={{Jct|state=CA|SR|86|name1=4th Street / [[Interstate 8 Business (El Centro, California)|I-8 Bus.]] west|city1=El Centro}}
|notes=Former [[U.S. Route 99 in California|US&nbsp;99]]
}}
{{CAint|exit
|mile=116.08
|exit=116
|road=Dogwood Road ([[County Route S31 (California)|CR&nbsp;S31]])
|notes=}}
{{CAint|exit
|location=none
|mile=118.06
|exit=118
|road={{Jct|state=CA|SR|111|city1=Brawley|city2=Indio|location3=Calexico}}
|notes=Signed as exits&nbsp;118A (south) and 118B (north)}}
{{CAint|exit
|location=none
|mile=119.66
|exit=120
|road=Bowker Road
|notes=}}
{{CAint|exit
|location=none
|mile=124.90
|exit=125
|road={{Jct|state=CA|SR|7|dir1=south|road|Orchard Road ([[County Route S32 (California)|CR&nbsp;S32]])}}
|notes=}}
{{CAint|exit
|location=none
|mile=127.61
|exit=128
|road=Bonds Corner Road
|notes=Former [[California State Route 115|SR&nbsp;115]]}}
{{CAint|exit
|location=none
|mile=130.62
|exit=131
|road={{Jct|state=CA|SR|115|dir1=north|name1=Van Der Linden Road|city1=Holtville}}
|notes=}}
{{CAint|exit
|location=none
|mile=142.87
|exit=143
|road={{Jct|state=CA|SR|98|dir1=west|city1=Calexico}}
|notes=}}
{{CAint|exit
|location=none
|mile=145.95
|exit=146
|road=Brock Research Center Road
|notes=Serves [[Brock Reservoir]]}}
{{CAint|exit
|location=none
|mile=150.60
|exit=151
|road=[[Gordons Well, California|Gordons Well]]
|notes=Former [[U.S. Route 80 in California|US&nbsp;80]] west}}
{{CAint|exit
|location=none
|mile=155.82
|exit=156
|road=Grays Well Road
|notes=}}
{{CAint|exit
|location=none
|mile=158.81
|exit=159
|road=Ogilby Road ([[County Route S34 (California)|CR&nbsp;S34]])
|notes=}}
{{CAint|exit
|location=Felicity
|mile=163.69
|exit=164
|road=Sidewinder Road
|notes=}}
{{CAint|exit
|type=incomplete
|location=none
|mile=164.30
|place=Agricultural Inspection Station (westbound only)
}}
{{CAint|exit
|location=Araz Junction
|mile=165.73
|exit=166
|road={{Jct|state=CA|SR|186|dir1=south|name1=Algodones Road|city1=Andrade|location2=[[Mexico]]}}
|notes=Former {{jct|state=CA|US|80|dir1=east|noshield1=yes}}
}}
{{CAint|exit
|location=Fort Yuma Indian Reservation
|lspan=2
|mile=169.97
|exit=170
|road=Winterhaven Drive ([[Interstate 8 Business (Winterhaven, California)|I-8 Bus.]] east)
|notes=Western terminus of I-8 Bus.}}
{{CAint|exit
|mile=171.54
|exit=172
|road=Fourth Avenue (SR 8U south<ref name="SR8U">{{cite web|url=https://postmile.dot.ca.gov/PMQT/PostmileQueryTool.html?type=C&mode=L&lat=32.732833&long=-114.624699&lat2=32.729148&long2=-114.624538|title=Route 8U: Postmile IMP T96.456 to IMP 96.946|website=Postmile Services Postmile Query Tool|publisher=Caltrans|accessdate=March 21, 2025}}</ref> / [[Interstate 8 Business (Winterhaven, California)|I-8 Bus.]])&nbsp;– [[Winterhaven, California|Winterhaven]]
|notes=Former {{jct|state=CA|US|80|noshield1=yes}}
}}
{{jctbridge|exit
|river=[[Colorado River]]
|river_wide=yes
|mile=171.98
|mile2=0.00
|line=y
|place=[[California]]–[[Arizona]] line}}
{{AZint|exit
|sspan=31
|county=Yuma
|cspan=15
|location=Yuma
|lspan=5
|mile=0.59
|exit=1
|road=Redondo Center Drive / Giss Parkway
|notes=Redondo Center Drive not signed westbound}}
{{AZint|exit
|mile=2.23
|exit=2
|road={{jct|state=AZ|US|95|name1=16th Street}}
|notes=}}
{{AZint|exit
|mile=3.98
|exit=3
|road=Avenue 3E
|notes=Former [[Former state routes in Arizona#State Route 280|SR&nbsp;280]]}}
{{AZint|exit
|mile=7.66
|exit=7
|road={{jct|state=AZ|SR|195|dir1=south|name1=Araby Road|city1=San Luis}}
|notes=}}
{{AZint|exit
|mile=9.44
|exit=9
|road={{jct|state=AZ|BL|8|dab1=Yuma|dir1=west|name1={{jct|state=AZ|US-Hist|80|dir1=west|noshield=yes}}|road|Avenue 8{{frac|1|2}}E}}
|notes=Eastern terminus of I-8 BL; former {{jct|state=AZ|US|80|dir1=west|noshield1=yes}}}}
{{AZint|exit
|location=Fortuna Foothills
|lspan=2
|mile=12.27
|exit=12
|road=Fortuna Road
|notes=}}
{{AZint|exit
|mile=14.28
|exit=14
|road=Foothills Boulevard
|notes=}}
{{AZint|exit
|location=none
|mile=21.06
|exit=21
|road={{jct|state=AZ|US-Hist|80|dir1=east|noshield=yes|city1=Dome Valley}}
|notes=Former {{jct|state=AZ|US|80|dir1=east|noshield1=yes}}
}}
{{AZint|exit
|location=Wellton
|mile=30.84
|exit=30
|road=Avenue 29E&nbsp;– [[Wellton, Arizona|Wellton]]
|notes=}}
{{AZint|exit
|location=Noah
|mile=37.99
|exit=37
|road=Avenue 36E&nbsp;– [[Roll, Arizona|Roll]]
|notes=}}
{{AZint|exit
|location=none
|mile=42.10
|exit=42
|road=Avenue 40E&nbsp;– [[Tacna, Arizona|Tacna]]
|notes=}}
{{AZint|exit
|location=none
|mile=54.98
|exit=54
|road={{jct|state=AZ|US-Hist|80|dir1=west|noshield1=yes|road|Avenue 52E|location1=[[Mohawk Valley (Arizona)|Mohawk Valley]]}}
|notes=Former {{jct|state=AZ|US|80|dir1=west|noshield1=yes}}}}
{{AZint|exit
|location=none
|mile=67.49
|exit=67
|road={{jct|state=AZ|US-Hist|80|dir1=east|noshield=yes|city1=Dateland}}
|notes=}}
{{AZint|exit
|location=none
|mile=73.53
|exit=73
|road={{jctname|state=AZ|US-Hist|80|dir1=west|noshield1=yes|name1=Aztec Road}}
|notes=}}
{{AZint|exit
|location=none
|mile=78.51
|exit=78
|road=Spot Road
|notes=}}
{{AZint|exit
|county=Maricopa
|cspan=9
|location=none
|mile=87.10
|exit=87
|road=[[Sentinel, Arizona|Sentinel]], [[Hyder, Arizona|Hyder]], [[Agua Caliente, Arizona|Agua Caliente]]
|notes=}}
{{AZint|exit
|location=none
|mile=102.34
|exit=102
|road=Painted Rock Road
|notes=Serves [[Painted Rock Petroglyph Site]]
}}
{{AZint|exit
|location=none
|mile=106.56
|exit=106
|road=Paloma Road
|notes=}}
{{AZint|exit
|location=Gila Bend
|lspan=4
|mile=111.49
|exit=111
|road=Citrus Valley Road
|notes=}}
{{AZint|exit
|mile=115.68
|exit=115
|road={{jct|state=AZ|BL|8|dab1=Gila Bend|dir1=east|noshield1=yes|name1={{jct|state=AZ|US-Hist|80|dir1=east|noshield=yes}}|AZ|85|<!--dir2=south|-->city1=Phoenix|city2=Ajo}}
|notes=Former {{jct|state=AZ|US|80|dir1=east|noshield1=yes}}<!--future west end of SR 85 concurrency-->
}}
{{AZint|exit
|type=unbuilt
|mile=
|exit=118
|road={{jct|state=AZ|SR|85|dir1=north}}
|notes=Future interchange<!--future east end of SR 85 concurrency--><ref>{{cite web |url = https://azdot.gov/docs/default-source/environmental-planning-library/sr85_gila_bend_final_ea.pdf?sfvrsn=2 |archive-url = https://web.archive.org/web/20160409162236/https://azdot.gov/docs/default-source/environmental-planning-library/sr85_gila_bend_final_ea.pdf?sfvrsn=2 |url-status = dead |title = Final Environmental Assessment and Section 4(f) Evaluation |publisher = [[Arizona Department of Transportation]] |date = February 2010 |archive-date = April 9, 2016 |access-date = September 18, 2019 }}</ref>
}}
{{AZint|exit
|mile=119.47
|exit=119
|road={{jctname|state=AZ|BL|8|dab1=Gila Bend|dir1=west|noshield1=yes|name1=Butterfield Trail|to2=1|AZ|85|dir2=north|I|10}}
|notes=Former {{jct|state=AZ|SR|84|dir1=west|noshield1=yes}}
}}
{{AZint|exit
|location=none
|mile=140.86
|exit=140
|road=Freeman Road
}}
{{AZint|exit
|location=none
|mile=144.60
|exit=144
|road=Vekol Valley Road
}}
{{AZint|exit
|county=Pinal
|cspan=7
|location=none
|mile=151.73
|exit=151
|road={{jct|state=AZ|AZ|84|dir1=east|to2=to|AZ|347|dir2=north|city1=Maricopa}}
|notes=}}
{{AZint|exit
|location=none
|mile=161.61
|exit=161
|road=[[Stanfield, Arizona|Stanfield]]
|notes=}}
{{AZint|exit
|location=none
|mile=167.61
|exit=167
|road=Montgomery Road
|notes=}}
{{AZint|exit
|location=none
|mile=169.72
|exit=169
|road=Bianco Road
|notes=}}
{{AZint|exit
|location=none
|mile=172.62
|exit=172
|road=Thornton Road&nbsp;– [[Casa Grande, Arizona|Casa Grande]]
|notes=}}
{{AZint|exit
|location=none
|mile=174.62
|exit=174
|road=Trekell Road&nbsp;– [[Casa Grande, Arizona|Casa Grande]]
|notes=}}
{{AZint|exit
|location=Casa Grande
|mile=178.36
|exit=178
|road={{jct|state=AZ|I|10|city1=Phoenix|city2=Tucson}}
|notes=Signed as exits 178A (west) and 178B (east); additional entrance from Sunland Gin Road; exit 199 on I-10}}
{{jctbtm|exit|col=8|keys=<!--concur,-->incomplete,unbuilt}}

==Auxiliary routes==
[[File:Business Loop 8.svg|thumb|right|100px|Business I-8 shield]]
{{main|Business routes of Interstate 8}}
There are no three-digit auxiliary routes of I-8. However, there are four signed business routes related to I-8 that provide additional access to particular towns or cities:
*[[El Cajon Boulevard]] passes through downtown El Cajon.
*The El Centro business loop runs along Adams Avenue in downtown El Centro.
*The Winterhaven–Yuma business loop begins in Winterhaven before crossing the Colorado River into Yuma and providing access to the downtown area, ending in eastern Yuma.
*The Gila Bend business loop connects with Arizona State Route&nbsp;85.<ref name="tgsd"/><ref name="gmaps">{{google maps|url=https://www.google.com/maps/dir/32.75474,-117.23561/32.820893,-111.690445/@32.6844638,-115.5521141,8z?hl=en|title=Interstate 8|access-date=December 18, 2014}}</ref>

==See also==
*{{portal-inline|Arizona}}
*{{portal-inline|California}}
*{{portal-inline|California Roads}}
*{{portal-inline|U.S. Roads}}

==References==
===Footnotes===
{{reflist|30em}}

===Works cited===
{{refbegin}}
*{{cite book |title = Roadside History of California |publisher = Mountain Press Publishing Company |last = Pittman |first = Ruth |year = 1995 |location = Missoula, Montana |isbn = 978-0-87842-318-7 |oclc = 32396018 }}
*{{cite book |title = Roadside History of Arizona |edition = 2nd |publisher = Mountain Press Publishing Company |last = Trimble |first = Marshall |year = 2004 |location = Missoula, Montana |isbn = 978-0-87842-471-9 |oclc = 12945147 }}
{{refend}}

==External links==
{{Attached KML|display=title,inline}}
{{Commons category|Interstate 8}}
{{CASR external links|I|8}}
*[http://www.cahighways.org/001-008.html#008 Interstate 8] at ''California Highways''
*[http://www.interstate-guide.com/i-008.html Interstate 8] {{Webarchive|url=https://web.archive.org/web/20120221032009/http://www.interstate-guide.com/i-008.html |date=February 21, 2012 }} at the ''Interstate Guide''
*Interstate 8 in [http://www.aaroads.com/california/i-008_ca.html California] and [http://www.aaroads.com/guide.php?page=i0008az Arizona] at ''AA Roads''
*[http://www.floodgap.com/roadgap/209/ Old SR&nbsp;209 and the Cabrillo National Monument] at ''Floodgap Roadgap''

{{interstates}}

{{DEFAULTSORT:I08}}
[[Category:Interstate 8| ]]
[[Category:Gila River|Gila River]]
[[Category:Interstate Highway System|08]]
[[Category:Interstate Highways in California|08]]
[[Category:Interstate Highways in Arizona|08]]
[[Category:Southern California freeways|008]]
[[Category:Roads in San Diego County, California]]
[[Category:Roads in Imperial County, California]]
[[Category:Transportation in Yuma County, Arizona]]
[[Category:Transportation in Maricopa County, Arizona]]
[[Category:Transportation in Pinal County, Arizona]]