 Interstate 184 | ||||
|---|---|---|---|---|
| Boise Connector | ||||
 I-184 highlighted in red | ||||
| Route information | ||||
| Auxiliary route ofI-84 | ||||
| Maintained byITD | ||||
| Length | 3.62 mi[1][2] (5.83 km) | |||
| Existed | 1968–present | |||
| History | Completed in 1992 | |||
| NHS | Entire route | |||
| Major junctions | ||||
| West end |   I-84 /US 30 inBoise | |||
| East end |   US 20 /US 26 in Boise | |||
| Location | ||||
| Country | United States | |||
| State | Idaho | |||
| Counties | Ada | |||
| Highway system | ||||
| ||||
| ||||
Interstate 184 (I-184) is a shortauxiliary Interstate Highway inBoise, Idaho, United States. The only auxiliary Interstate in Idaho, it is a spur route ofI-84 that connects the freeway toDowntown Boise, terminating atUS Highway 20 (US 20) andUS 26 on the west side of theBoise River.
The western section of the freeway, named theBoise Connector, opened to traffic in December 1968. It was designated asI-180N until a renumbering of I-84 that was approved in 1979. I-184 was extended to a new interchange with US 20 and US 26 in 1992 as part of a new Downtown Boise connector and bridge.
I-184, also known as the Boise Connector or just the "Connector", is a short, six-lane urban freeway that travels between a junction withI-84 and the west side ofDowntown Boise.[3] Its western terminus is the "Flying Wye" interchange with I-84 andUS 30 in southwestern Boise, which includes a braided ramp for adjacent exits on both freeways.[3][4] I-184 travels northeast and crosses over a spur railroad near an interchange with Franklin Street on the south side of theBoise Towne Square shopping mall. The freeway then intersects Curtis Road near theSaint Alphonsus Regional Medical Center and turns due east along Fairview Avenue, which acts as afrontage road. On the west side of theBoise River in Rotary Park, I-184 terminates after an interchange withUS 20 andUS 26, which serve northwestern Boise andGarden City on Chinden Boulevard. US 20 and US 26 supersede I-184 and cross into Downtown Boise, where they split into thepaired one-way Front and Myrtle streets.[3][5]
I-184 is the only auxiliary Interstate Highway in Idaho and the state's shortest, at 3.62 miles (5.83 km).[3] The highway is maintained by theIdaho Transportation Department (ITD), which conducts an annual survey of traffic on certain highway segments that is expressed in terms ofannual average daily traffic (AADT), a measure of traffic volume for any average day of the year. The sole traffic recording device on I-184, tracking eastbound traffic near Cole Road, reported a daily average of 78,034 vehicles on the highway in 2022.[6] From 2015 to 2022, traffic volumes increased by 3 percent—slower than other area roads—and congestion is typically worse near the Flying Wye interchange during the eveningrush hour.[7] According to the ITD, the average speed of traffic on the freeway in 2022 was 66 miles per hour (106 km/h), above the postedspeed limit of 60 miles per hour (97 km/h).[8][9]
The Boise Connector was planned in the early 1960s to connect the Boise freeway bypass to Downtown Boise and its inner neighborhoods.[10] One version of the plan proposed a full loop bisecting Downtown Boise to carry I-80N, but it was rejected in favor of a less costly spur route.[11] The westernmost section of the connector, including a sprawling wye interchange with I-80N, began construction in July 1965 and cost $9.5 million to build.[12] It was opened to traffic on December 12, 1968, a year before the rest of the bypass,[3][13] and initially terminated at Garden Street.[14]
 Interstate 180N | |
|---|---|
| Location | Boise |
| Existed | 1968–1980 |
The freeway was numberedInterstate 180N (I-180N) until October 13, 1979, when I-184 was adopted to match I-84, which was planned to succeed I-80N effective May 1, 1980.[15][16] It was the only signed suffixed auxiliary Interstate Highway in the nation.[3] Parts of the connector were signed as part ofState Highway 55 (SH-55)[17] until it was realigned onto Eagle Road in September 1990.[18][19] Eastbound traffic on US 30 was also used a section of I-180N before merging onto Main Street and Fairview Avenue.[20] This concurrency was eliminated in 1980, when US 30 was relocated onto I-84.[21][22]
Construction of the Broadway–Chinden Connector, which would connect I-184 with downtown Boise, began in January 1988 and cost $60 million to complete.[23] The new bridge across the Boise River was opened on August 7, 1992, replacing a pair of smaller bridges to the north.[24] The westernmost segment of I-184, including the Flying Wye interchange, was rebuilt from 1999 to 2004 to accommodate an additional set of lanes.[10] The project cost $86 million[25] (equivalent to $136 million in 2024[26]) and was delayed approximately six months due to financial constraints and delays in bridge construction in the initial phase of the project.[27]
The entire route is inBoise,Ada County.
| mi[1] | km | Exit | Destinations | Notes | ||
|---|---|---|---|---|---|---|
| 0.00 | 0.00 |  I-84 west (US 30 west) –Nampa | Western terminus; I-84 exit 49 | |||
| 0.67 | 1.08 | 0 |   I-84 east (US 30 east) –Mountain Home | Westbound exit and eastbound entrance; servesBoise Airport | ||
| 1.08 | 1.74 | 1A | Franklin Road | Westbound exit also signed as "Milwaukee Street" | ||
| 1.33 | 2.14 | 1B | Cole Road | Westbound exit and eastbound entrance | ||
| 2.54 | 4.09 | 2 | Curtis Road | Westbound exit also signed as "Fairview Avenue" | ||
| 2.81– 3.09 | 4.52– 4.97 | 3 | Fairview Avenue | Westbound access is part of exit 2 | ||
| 3.62 | 5.83 |  US 20 /US 26 east | No access to US-20/US-26 west; continuation as freeway beyond eastern terminus | |||
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi | ||||||
Media related toInterstate 184 (Idaho) at Wikimedia Commons
Auxiliary routes of highways designated as Interstate 84 | ||
|---|---|---|
| Oregon–Utah segment |  | |
| Pennsylvania–Massachusetts segment | ||
1Former | ||
