List of Interstate Highways in Idaho
{{Short description|none}}
{{Use mdy dates|date=February 2025}}
{{infobox state highway system
|title= Interstate Highways of the Idaho State Highway System
|shields={{infobox road/shieldmain/USA|state=ID|type=I|route=15}}{{infobox road/shieldmain/USA|state=ID|type=I|route=184}}{{infobox road/shieldmain/USA|state=ID|type=BL|route=90}}
|caption=Typical Interstate highway markers
|map_alt=
|maint=ITD
|length_mi={{sum|535.60|75.71}}
|length_ref={{cite web |year=2015 |title=National Highway Freight Network Map and Tables for Idaho |url=https://ops.fhwa.dot.gov/Freight/infrastructure/ismt/state_maps/states/idaho.htm |publisher=Federal Highway Administration |accessdate=December 11, 2022}}
|formed=1956
|interstate=Interstate n (I-n)
|us=U.S. Highway n (US-n)
|statehwy=Idaho State Highway n (SH-n)
|links=ID
|map={{Maplink|frame=yes|plain=yes|frame-align=center|frame-width=160
|type=line|from=Interstate 15 in Idaho.map
|type2=line|from2=Interstate 84 in Idaho.map
|type3=line|from3=Interstate 86.map
|type4=line|from4=Interstate 90 in Idaho.map
|type5=line|from5=Interstate 184.map
|id6=Q1221|type6=line|stroke-color6=#000|stroke-width6=1
}}
|map_custom=yes
|map_notes=Interstate Highways highlighted in red}}
The Interstate Highways in Idaho are the segments of the Dwight D. Eisenhower National System of Interstate and Defense Highways owned and maintained by the Idaho Transportation Department (ITD) in the U.S. state of Idaho. The state has five Interstate Highways that total approximately {{convert|611|mi|km}} in length.
__TOC__{{Clear}}
Mainline highways
{{routelist top|length_ref={{cite web |title=Milepoint Logs |url=http://itd.idaho.gov/milepointlog/ |publisher=Idaho Transportation Department |accessdate=February 15, 2017}}}}
{{routelist row
|state=ID
|type=I
|route=15
|length_mi=196.000
|terminus_a=I-15 near Woodruff
|terminus_b=I-15 at Monida Pass
|established=1957
|notes=
}}
{{routelist row
|state=ID
|type=I 1961
|route=15W
|sortkey=I0015W
|length_mi=62.850
|terminus_a=I-84 / US 30 near Declo
|established=1957
|decommissioned=1978
|notes=Became I-86
}}
{{routelist row
|state=ID
|type=I 1961
|route=80N
|sortkey=I0080N
|length_mi=275.650
|terminus_a=I-84 near Fruitland
|terminus_b=I-84 near Black Pine
|established=1957
|decommissioned=1980
|notes=Became I-84
}}
{{routelist row
|state=ID
|type=I
|route=84
|length_mi=275.650
|terminus_a=I-84 near Fruitland
|terminus_b=I-84 near Black Pine
|established=1980
|notes=Designated as I-80N until 1980
}}
{{routelist row
|state=ID
|type=I
|route=86
|length_mi=62.850
|terminus_a=I-84 / US 30 near Declo
|established=1978
|notes=Designated as I-15W until 1978
}}
{{routelist row
|state=ID
|type=I
|route=90
|length_mi=73.888
|terminus_a=I-90 in State Line
|terminus_b=I-90 at Lookout Pass
|established=1957
|notes=
}}
{{routelist row
|state=ID
|type=I
|route=180N
|length_mi=3.620
|terminus_a=I-84 / US 30 in Boise
|terminus_b=US 20 / US 26 in Boise
|established=1970
|decommissioned=1979
|notes=Became I-184
}}
{{routelist row
|state=ID
|type=I
|route=184
|length_mi=3.620
|terminus_a=I-84 / US 30 in Boise
|terminus_b=US 20 / US 26 in Boise
|established=1979
|notes=Designated as I-180N until 1979, completed in 1990
}}
{{routelist bottom|keys=former}}
Business routes
{{routelist row
|state=ID
|type=BL
|route=15
|dab=McCammon
|length_mi=4.338
|terminus_a=I-15/US 91 exit 44 near McCammon
|terminus_b=I-15/US 30/US 91 exit 47 in McCammon
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=15
|dab=Inkom
|length_mi=1.000
|terminus_a=I-15/US 30/US 91 exit 57 in Inkom
|terminus_b=I-15/US 30/US 91 exit 58 in Inkom
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=15
|dab=Pocatello
|length_mi=5.560
|terminus_a=I-15/US 30/US 91 exit 67 in Pocatello
|terminus_b=I-15 exit 69 in Pocatello
|established=
|established_ref=
|notes=US 30 and US 91 branches off I-15 at its southern end
}}
{{routelist row
|state=ID
|type=BL
|route=15
|dab=Blackfoot
|length_mi=4.802
|terminus_a=I-15 exit 89 southwest of Blackfoot
|terminus_b=I-15/US 26 exit 93 in Blackfoot
|established=
|established_ref=
|notes=I-15 and US 26 begin concurrency at northern end
}}
{{routelist row
|state=ID
|type=BL
|route=15
|dab=Idaho Falls
|length_mi=7.230
|terminus_a=I-15/US 26 exit 116 near Idaho Falls
|terminus_b=I-15/US 20 Bus. exit 118 in Idaho Falls
|established=
|established_ref=
|notes=Concurrent with Us 26 at south end and US 20 Bus. at north end
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Caldwell–Nampa
|length_mi=12.557
|terminus_a=I-84/US 20/US 26/US 30 exit 27 in Caldwell
|terminus_b=I-84/US 30/SH-55 exit 38 in Nampa
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Boise
|length_mi=
|terminus_a=I-84/US 30 exit 49 west of Boise
|terminus_b=I-84/US 20/US 26/US 30 exit 54 in Boise
|established=
|established_ref=
|decommissioned=yes
|decommissioned_ref=
|notes=Now part of I-184, US 20, and US 26
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Mountain Home
|length_mi=5.985
|terminus_a=I-84/US 20/US 26/US 30 exit 90 near Mountain Home
|terminus_b=I-84/US 26/US 30 exit 99 near Mountain Home
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Hammett
|length_mi=
|terminus_a=I-84/US 26/US 30/SH-78 exit 112 in Hammett
|terminus_b=I-84/US 26/US 30 exit 114 near Hammett
|established=
|established_ref=
|notes=Runs concurrent with SH-78 at west end
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Glenns Ferry
|length_mi=1.425
|terminus_a=I-84/US 26/US 30 exit 120 in Glenns Ferry
|terminus_b=I-84/US 26/US 30 exit 121 in Glenns Ferry
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Bliss
|length_mi=3.518
|terminus_a=I-84/US 26/US 30 exit 137 near Bliss
|terminus_b=I-84/US 26 exit 141 in Bliss
|established=
|established_ref=
|notes=Runs concurrent with US 30 near whole length. Road continues as US 26 at east end
}}
{{routelist row
|state=ID
|type=BL
|route=84
|dab=Burley–Heyburn
|length_mi=6.56
|terminus_a=I-84/SH-27 exit 208 near Burley
|terminus_b=I-84/US 30/SH-24 near Heyburn
|established=
|established_ref=
|notes=Entirely concurrent with SH-27 at west end then US 30 to east end. Road continues as SH-24
}}
{{routelist row
|state=ID
|type=BL
|route=86
|dab=American Falls
|length_mi=6.475
|terminus_a=I-86/US 30/SH-37 exit 36 near Neeley
|terminus_b=I-86/US 30/SH-39 exit 40 in American Falls
|established=1972
|established_ref=
|notes=Concurrent with SH-39 toward east end
}}
{{routelist row
|state=ID
|type=BL
|route=90
|dab=Post Falls
|length_mi=5.640
|terminus_a=I-90 exit 2 west of Post Falls
|terminus_b=I-90 exit 6 in Post Falls
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=90
|dab=Coeur d'Alene
|length_mi=3.834
|terminus_a=I-90 exit 11 near Coeur d'Alene
|terminus_b=I-90 exit 15 in Coeur d'Alene
|established=
|established_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BL
|route=90
|dab=Kellogg
|length_mi=1.4
|terminus_a=I-90 exit 49 near Kellogg
|terminus_b=I-90 exit 51 in Kellogg
|established=
|established_ref=
|decommissioned=yes
|decommissioned_ref=
|notes=none
}}
{{routelist row
|state=ID
|type=BS
|route=90
|dab=Osburn
|length_mi=3.966
|terminus_a=I-90 exit 57 in Osburn
|terminus_b=E. Mullan Ave. in downtown Osburn
|established=
|established_ref=
|notes=Originally a business loop that ran from exit 57 to exit 60 to Silverton via Silver Valley Road. Split into two separate spurs
}}
{{routelist row
|state=ID
|type=BS
|route=90
|dab=Silverton
|length_mi=0.12
|terminus_a=I-90 exit 60 in Silverton
|terminus_b=Silver Valley Rd south of Silverton
|established=
|established_ref=
|notes=Part of original loop that once ran from I-90 exit 57 in Osburn to exit 60 in Silverton via Silver Valley road. Split into two separate spurs
}}
{{routelist row
|state=ID
|type=BL
|route=90
|dab=Wallace
|length_mi=1.243
|terminus_a=I-90 exit 61 near Wallace
|terminus_b=I-90 exit 62 in Wallace
|established=
|established_ref=
|notes=Originally part of I-90 that contained a traffic signal before entering Wallace. Became I-90BL when I-90 was rerouted north as a full freeway
}}
{{routelist row
|state=ID
|type=BL
|route=90
|dab=Mullan
|length_mi=1.000
|terminus_a=I-90 exit 68 in Mullan
|terminus_b=I-90 exit 69 near Mullan
|established=
|established_ref=
|notes=none
}}
{{routelist bottom|keys=former}}
See also
{{portal|U.S. Roads}}
References
{{reflist}}