Business routes of Interstate 8
{{short description|none}}
{{Use mdy dates|date=March 2025}}
{{Notability|date=April 2024}}
{{Primary|date=April 2024}}
{{infobox road
|country=USA
|type=BL
|route=8
|maint=none}}
There are five business routes of Interstate 8 (I-8).
The portions of the I-8 business routes through California are mostly unsigned. All Interstate business routes in California are assigned by the California Department of Transportation (Caltrans), but are not maintained by Caltrans unless they overlay other routes of the state highway system. Local authorities may request route assignment from the Caltrans Transportation System Information Program, and all requests require approval of the executive committee of the American Association of State Highway and Transportation Officials (AASHTO).{{cite book |chapter-url = http://www.dot.ca.gov/hq/oppd/hdm/pdf/english/chp0020.pdf |title = Highway Design Manual |chapter = Chapter 20, Index 21.2 |author = Division of Design |date = May 7, 2012 |publisher = California Department of Transportation |page = 3 |access-date = September 9, 2014 }}
__TOC__{{-}}
El Cajon loop
{{Infobox road small
|state=CA
|type=BL
|route=8
|location=El Cajon–Lakeside, California
|length_mi=8.15
}}
{{see also|El Cajon Boulevard}}
Business Loop 8 (I-8 Bus.) begins as El Cajon Boulevard at an interchange with I-8, loosely paralleling the freeway on the northern side. The loop passes through Bostonia and Lakeview before ending at the Lake Jennings Park Road interchange with I-8.{{google maps |url = https://www.google.com/maps/place/Alpine,+CA/@32.8216371,-116.9033538,13z/data=!4m2!3m1!1s0x80d960efbcb72153:0xee132b6842c123b1 |title = El Cajon Boulevard |access-date = November 2, 2014 }}
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Major intersections
{{jcttop|state=CA|county=San Diego|length_ref=}}
{{CAint
|type=incomplete
|mile=0.00
|location=El Cajon
|lspan=3
|road={{jct|state=CA|I|8|dir1=west|name1=Mission Valley Freeway}}
|notes=Western terminus; I-8 exit 15; no access to I-8 east
}}
{{CAint
|mile=
|road=Chase Avenue, Boulevard Place
|notes=Partial interchange eastbound, at-grade intersections westbound
}}
{{CAint
|type=incomplete
|mile=3.77
|mile2=3.86
|road={{jct|state=CA|I|8|dir1=east|name1=Mission Valley Freeway}}
|notes=I-8 west exit 20A; no access to I-8 west
}}
{{CAint
|location=Lakeside
|mile=7.98
|mile2=8.15
|road={{jct|state=CA|I|8|city1=San Diego|city2=El Centro}}
|notes=Eastern terminus; road continues south as Lake Jennings Park Road
}}
{{jctbtm|keys=incomplete}}
{{Clear}}
Alpine loop
{{Infobox road small
|header_type=former
|state=CA
|type=BL
|route=8
|location=Alpine, California
}}
Business Loop 8 (I-8 Bus.) in Alpine spanned from I-8 exit 30 to exit 33 and was mostly former US 80 along Alpine Drive.
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==El Centro loop==
{{Infobox road small
|state=CA
|type=BL
|route=8
|location=El Centro, California
|length_mi=4.25
}}
Business Loop Interstate 8 (I-8 Bus.) is a business loop route that diverges from I-8 in El Centro, California, to pass through the downtown area. I-8 Bus. originates and terminates with I-8 and acts as a direct link to El Centro as I-8 bypasses the downtown area.
The I-8 Bus. path through El Centro traces roughly three sides of a rectangle with I-8 constituting the fourth side. I-8 Bus. begins at its western terminus with I-8 by going north along Imperial Avenue. When I-8 Bus. reaches the intersection of Adams Avenue it turns east along that road. Along this stretch, I-8 Bus. is joined by State Route 86 (SR 86) which approaches from the north along Imperial Avenue, and by Imperial County Route S80 which approaches from the west along Adams Avenue. The three routes continue joined as Adams Avenue ends and turns south along Fourth Avenue where S80 then turns to continue east. I-8 Bus. and SR 86 continue south running concurrent until I-8 Bus. reaches its eastern terminus with I-8.{{google maps |url = https://maps.google.com/maps?f=d&hl=en&geocode=2863822521104466740,32.754740,-117.235610&saddr=I-8+E+%4032.754740,+-117.235610&daddr=32.820893,-111.690445&mra=mi&mrsp=1,0&sz=14&sll=32.812382,-111.692848&sspn=0.032606,0.05785&ie=UTF8&ll=32.87036,-114.345703&spn=4.17026,7.404785&z=7 |title = Overview Map of I-8 in California |access-date = February 16, 2008 }}
Only the portion of I-8 Bus. that runs concurrently with SR 86 is maintained by the state.{{Caltrans bridgelog |date = July 2007 }} Along its concurrency with SR 86, I-8 Bus. is designated as part of the Juan Bautista de Anza National Historic Trail.{{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 |accessdate = October 6, 2008 }}
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Major intersections
{{jcttop|state=CA|county=Imperial|location=El Centro|length_ref=}}
{{CAint
|mile=0.00
|mile2=0.33
|road={{jct|state=CA|I|8|name1=Kumeyaay Highway|city1=San Diego|location2=Yuma}}
|notes=Western terminus; I-8 exit 114
}}
{{CAint
|type=concur
|mile=1.69
|road={{jct|state=CA|SR|86|dir1=north|name1=Imperial Avenue north|CR|S80|dir2=west|name2=Adams Avenue west|city1=Brawley|city2=Los Angeles}}
|notes=Western end of SR 86/CR S80 concurrency; former US 99 north/US 80 west
}}
{{CAint
|type=concur
|mile=2.90
|road={{jct|state=CA|CR|S80|dir1=east|name1=Main Street|city1=Holtville}}
|notes=Eastern end of CR S80 concurrency; former US 80 east
}}
{{CAint
|type=concur
|mile=4.19
|mile2=4.25
|road={{jct|state=CA|I|8|SR|86|dir2=south|name1=Kumeyaay Highway|name2=4th Street south|city1=San Diego|location2=Yuma}}
|notes=Eastern terminus; eastern end of SR 86 concurrency; former US 99 south; I-8 exit 115
}}
{{jctbtm|keys=concur}}
{{Clear}}
Winterhaven–Yuma loop
{{Infobox road small
|country=USA
|type=BL
|route=8
|location=Winterhaven, California – Yuma, Arizona
|name=Interstate 8 Business
State Business Route 8 (1)
|length_mi=14.84
|length_ref={{google maps |url = https://www.google.com/maps/dir/32.7364135,-114.6507775/32.7318542,-114.6246688/32.7293254,-114.6246398/32.6985234,-114.6246292/32.6699836,-114.5214383/32.6702697,-114.4954775/32.6704165,-114.486608/@32.7051611,-114.6387349,12z/data=!3m1!4b1!4m14!4m13!1m0!1m0!1m0!1m5!3m4!1m2!1d-114.5924468!2d32.6694259!3s0x80d65f3ffd67578f:0x9ad6b66262fbd50b!1m0!1m0!1m0!3e0 |title = Overview of Business Loop I-8 Winterhaven–Yuma |access-date = December 9, 2017 }}{{cite book |url = https://www.azdot.gov/docs/default-source/planning/2013shslog.pdf |title = 2013 ADOT Highway Log |author = Arizona Department of Transportation |author-link = Arizona Department of Transportation |pages = 531–533 |access-date = December 9, 2017 }}{{rp|531}}
|length_round=2
|formed=1966
}}
{{imageframe|width=260|content={{maplink|frame=yes|plain=yes|frame-align=center|frame-width=260|frame-lat=32.705|frame-long=-114.57|zoom=11|type=line|from=Interstate 8 Business (Winterhaven, California-Yuma, Arizona).map|stroke-width=3}}|caption=A map of the Winterhaven–Yuma business loop. The route is highlighted in red.|align=right}}
Business Loop 8 (I-8 Bus. or I-8 BL) begins at an interchange with I-8 and Winterhaven Drive in Winterhaven, California. The loop continues east, paralleling I-8 to the north and running concurrently with CR S24. I-8 Bus. then goes through downtown Winterhaven before CR S24 continues east and I-8 Bus. continues south, crossing I-8 again as well as the Colorado River into Yuma, Arizona. Passing to the west of Yuma Quartermaster Depot State Historic Park, I-8 BL goes through downtown Yuma as Fourth Avenue, intersecting US 95 after several blocks. The business loop curves to the east as 32nd Street, passing along the north side of Yuma International Airport and the south side of the Yuma Conservation Garden. East of the airport, I-8 BL passes through less-developed areas of eastern Yuma before ending at I-8.
It is one of very few Interstate business loops that is interstate in the sense of crossing a state line. The Arizona segment of the business loop is also a section of Historic US 80.
The segment in Winterhaven between the California–Arizona state line and I-8 was never relinquished to local control after the decommissioning of US 80 and remains a California state highway. It carries the unsigned designation of Route 8U (for "unrelinquished").{{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 = California Department of Transportation |access-date = March 21, 2025 }}
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Major intersections
{{jcttop|state_col=state|length_ref=|dest_ref={{Cite report |url = http://aztransportationboard.gov/downloads/2018-072018-Agenda.pdf |title = Arizona State Transportation Board Meeting Agenda |date = July 20, 2018 |publisher = Arizona State Transportation Board |location = Show Low, Arizona |pages = 310–339 |access-date = June 16, 2019 }}}}
{{CAint
|sspan=4
|county=Imperial
|cspan=4
|location=none
|mile=0.00
|road={{jct|state=CA|I|8|city1=El Centro|location2=Yuma}}
|notes=Western terminus; I-8 exit 170}}
{{CAint
|type=concur
|location=Winterhaven
|lspan=2
|mile=0.39
|road={{jct|state=CA|CR|S24|dir1=west|name1=Araz Road}}
|notes=Western end of CR S24 concurrency; former US 80 west
}}
{{CAint
|type=concur
|mile=1.66
|road={{jct|state=CA|CR|S24|dir1=east|name1=Picacho Road}}
|notes=Eastern end of CR S24 concurrency; former US 80 east
}}
{{CAint
|location=none
|type=concur
|mile=2.01
|road={{jct|state=CA|I|8|city1=San Diego}}
|notes=Northern end of SR 8U; I-8 exit 172}}
{{jctbridge
|river=Colorado River
|type=concur
|river_wide=yes
|mile=2.18
|mile2=0.00
|line=y
|place=California–Arizona state line
(southern end of SR 8U)}}
{{AZint
|sspan=4
|county=Yuma
|cspan=4
|location=Yuma
|lspan=4
|type=concur
|mile=0.29
|road={{jct|state=AZ|US-Hist|80|dir1=west|name1=1st Street}}
|notes=Western end of Historic US 80 concurrency
}}
{{AZint
|mile=2.13
|road={{jct|state=AZ|US|95|to2=to|I|8|name1=16th Street|city1=Quartzsite|city2=San Luis}}
|notes=}}
{{AZint
|mile=10.47
|road={{jct|state=AZ|SR|195|dir1=south|to2=to|I|8|name1=Araby Road}}
|notes=}}
{{AZint
|mile=12.16
|mile2=12.66
|type=concur
|road={{jct|state=AZ|I|8|US-Hist|80|dir2=ends}}
|notes=Eastern terminus; eastern end of Historic US 80 concurrency, road continues as Frontage Road; I-8 exit 9}}
{{jctbtm|col=7|keys=concur}}
{{Clear}}
Gila Bend loop
{{Infobox road small
|state=AZ
|type=BL
|route=8
|location=Gila Bend, Arizona
|name=State Business Route 8 (3)
|length_mi=5.96
|established=1973
}}
{{imageframe|width=260|content={{maplink|frame=yes|plain=yes|frame-align=center|frame-width=260|frame-lat=32.937|frame-long=-112.712|zoom=12|type=line|from=Interstate 8 Business (Gila Bend, Arizona).map|stroke-width=3}}|caption=A map of the Gila Bend business loop. The route is highlighted in red.|align=right}}
State Business Route 8 (3) (also known as SR 8 Bus.) begins at an interchange with I-8 west of Gila Bend before passing under the freeway, continuing east and merging with SR 85 at a truck stop. As Pima Street, the two highways continue through downtown Gila Bend before I-8 BL turns south away from SR 85 as Butterfield Trail and ending at I-8 at a diamond interchange.{{google maps |url = https://www.google.com/maps/place/Gila+Bend,+AZ/@32.9407628,-112.718624,14z/data=!4m2!3m1!1s0x80d528408d307de3:0x6dea177bee0b822b |title = Business Loop I-8 Gila Bend |access-date = November 2, 2014 }}
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Major intersections
{{jcttop|state=AZ|county=Maricopa|length_ref=|dest_ref=}}
{{AZint
|type=incomplete
|location=Gila Bend
|lspan=4
|mile=117.28
|mile2=117.93
|road={{jct|state=AZ|I|8|US-Hist|80|dir2=begins|road|Frontage Road}} – San Diego
|notes=Western terminus; westbound entrance and eastbound exit; western terminus of Historic US 80; I-8 exit 115
}}
{{AZint
|type=concur
|mile=118.41
|road={{jct|state=AZ|SR|85|dir1=south|city1=Ajo|location2=Mexico|to2=to|I|8|dir2=east}}
|notes=Western end of SR 85 concurrency
}}
{{AZint
|type=concur
|mile=120.23
|road={{jct|state=AZ|US-Hist|80|dir1=east|name1=Old Highway 80}}
|notes=Eastern end of Historic US 80 concurrency; former US 80 east
}}
{{AZint
|type=concur
|mile=120.28
|road={{jct|state=AZ|SR|85|dir1=north|name1=Pima Street|to2=to|I|10|city1=Phoenix}}, Los Angeles
|notes=Eastern end of SR 85 concurrency
}}
{{AZint
|location=none
|mile=122.93
|mile2=123.18
|road={{jct|state=AZ|I|8|city1=Tucson|to2=to|I|10}}
|notes=Eastern terminus; I-8 exit 119
}}
{{jctbtm|keys=concur,incomplete}}
{{Clear}}