IDAHO HIGHWAYS

Idaho State Highway System
 Summary
 Interstate Highways
 U.S. Highways
 State Highways
 Idaho Highways @Wikipedia
 Idaho Highways @US-Highways.com

Related Pages
 Highway History
 Projects & Visions
 Idaho's Highway Future
 Idaho's Route Markers
 Highway Projects
 Idaho Home Page
 

SUMMARY

Idaho's Interstate system was started with the Interstate 15 being the first interstate highway to be opened in the state. The interstate system was completed in Idaho in 1974. Currently Idaho's interstate system consists of 612 miles of Primary Interstate highways and 154 miles of Business Loops. And one primary interstate, Interstate 86, is located entirely within the state.

INTERSTATE HIGHWAYS IN IDAHO

Idaho Interstate Routes
I-15 I-84 I-86
I-90 I-184

Idaho's Interstate system was started with the Interstate 15 being the first interstate highway to be opened in the state. The interstate system was completed in Idaho in 1974. Currently Idaho's interstate system consists of 612 miles of Primary Interstate highways and 154 miles of Business Loops. And one primary interstate, Interstate 86, is located entirely within the state.

currently there are no new plans to open new miles of interstate highway. Although there are some long range studies that show a possible bypass around Boise and the Treasure Valley, which could eventually be added to the interstate system. More information on future plans for Idaho's Interstates can be found on the Visions page.

When first numbered Interstates 84, 184 and 86 had different numbers (80N, 180N and 15W respectively). For more history about Idaho's interstates see the History page.

U.S. HIGHWAYS IN IDAHO

Idaho US Routes
US 2 US 12 US 20 US 26 US 30
US 89 US 91 US 93 US 95 US 195

Idaho's U.S. Routes were part of the first transcontinenntal interstate highway system built on the U.S. dating back to the mid 1920's. They were and still are today an integral part of statewide transportation. The states most important U.S. Routes are US-20, US-93 and US-95, as they connect a large number of communities not currently served by the interstate highway system. Currently Idaho's U.S highway system consists of 10 differently numbered U.S. highways, but previously there were as many as 18 different numbered routes in the past. Idaho's US highway system also consists of several "bannered" U.S. Routes as well such as SPUR and Business routes.

currently there are plans to upgrade hundreds of miles of US Routes throughout the state as part of ongoing plans and studies to address growing traffic volume. However there are no new plans to Add any new U.S Route numbers within the state. More information on future plans for Idaho's U.S. highways can be found on the Visions page.

When first laid out there were also several Split U.S routes as well such as US-30S and US-30N. For more history about Idaho's U.S. highways see the History page.

STATE HIGHWAYS IN IDAHO

Idaho State Highways
  1   3 4 5 6 7 8 9
  11   13 14   16     19
  21 22   24 25   27 28 29
  31 32 33 34   36 37 38 39
40 41   43 44 45 46 47 48  
50 51 52 53 54 55   57 58  
60 61 62   64   66 67   69
  71 72   74 75   77 78 79
  81           87    
              97   99
3 Digit Routes
128 162 200    

Idaho's state highway system has been in existence since the first numbered signed routes were posted in Idaho back in the late 1920's and 30's. Several of these routes have been renumbered over the years and rerouted onto better roads as well. State highways are crucial to statewide transportation. They connect the majority of Idaho's cities and communities to each other and to the national highway systems as well. Today many state highways play a more localized role connecting to communities as feeder routes, However there are still many state highways that provide a more inter-regional and statewide role such as SH-55 and SH-75. Currently Idaho's State highway system consists of 65 differently numbered state highways, some of them supplemented by local business routes and spurs.

currently there are plans to upgrade several state highways in Idaho, Including Upgrades and extensions to SH-16 to Emmett, and SH-75 toward Sun Valley and Ketchum. More information on future plans for Idaho's state highways can be found on the Visions page, or for more history about Idaho's state highways see the History page.