Interstate 115

{{Redirect|I-115|the isotope of iodine (I-115 or ¹¹⁵I)|Iodine-115}}

{{Infobox road

|state=MT

|type=I

|route=115

|map={{maplink|frame=yes|plain=yes|frame-align=center|frame-width=290|frame-lat=46.00|frame-long=-112.55|zoom=12|type=line|raw={{Wikipedia:Map data/Wikipedia KML/Interstate 115}}}}

|map_custom=yes

|map_notes=I-115 highlighted in red

|spur_type=I

|spur_of=15

|length_mi=1.194

|length_ref=

|established=1971

|direction_a=West

|terminus_a={{Jct|state=MT|I|15|I|90}} in Butte

|direction_b=East

|terminus_b={{jct|state=MT|BL|15|dab1=Butte|BL|90|dab2=Butte}} in Butte

|counties=Silver Bow

|previous_type=I

|previous_route=94

|next_type=MT

|next_route=117

}}

Interstate 115 (I-115) is a {{convert|1.194|mi|km|adj=mid|-long}} auxiliary Interstate Highway which connects I-15/I-90 to Butte in the U.S. state of Montana. The highway is concurrent with I-15 Bus./I-90 Bus. for its entire length. The highway travels from an incomplete interchange with I-15/I-90 through generally rural areas in western Butte. It also has an interchange with Excelsior Avenue before terminating. The entire route was built to Interstate standards during the 1960s, and was further changed in 2005.

Route description

I-115 begins at an interchange with I-15/I-90. As a four-lane highway with two lanes in each direction, I-115 heads east into downtown Butte. Before reaching exit 1, eastbound traffic makes a curve while westbound traffic goes to I-15/I-90 without making such a curve, therefore, that portion of I-115 contains a large median. The other portion at exit 1, however, is separated only by a curbed street median and does not have a Jersey barrier separating the two halves. Approximately {{convert|1|mi|spell=in}} from I-15/I-90, I-115 has its only interchange at Excelsior Avenue, which can be used to access the town of Walkerville. Excelsior Avenue is the only numbered exit along I-115, and the structure of the interchange directs motorists to stop and yield signs, as opposed to traffic signals for most exits in urban areas. I-115 ends at the overpass over Excelsior Avenue. It continues into Butte as I-15 Bus./I-90 Bus.{{Google maps|url=https://maps.google.com/maps?saddr=Exit+124&daddr=W+Iron+St&hl=en&ll=46.000539,-112.556906&spn=0.035952,0.055189&sll=46.004057,-112.5524&sspn=0.018094,0.027595&geocode=FY_4vQIda0RK-Q%3BFfX1vQIdVa9K-Q&mra=mrv&t=h&z=14|accessdate=December 20, 2013}}

History

File:Butte, Montana 1955 Yellow Book.jpg

The development of a freeway along the modern-day I-115 corridor was proposed in the 1950s. The 1955 General Location of National System of Interstate Highways, an early platform for what would become the Interstate Highway System, contained an inset of the proposed freeways in and around the city of Butte including an east–west freeway spur on the west side of the community.{{cite map |map-url=https://archive.org/stream/generallocationo00unitrich#page/50/mode/2up |title=General Location of National System of Interstate Highways Including All Additional Routes at Urban Areas Designated in September 1955 |map=Butte, Montana |page= 51 |scale= 1:63,360 |author= Bureau of Public Roads |publisher= Bureau of Public Roads |date=September 1955 |oclc= 4165975}} Designated as part of the Interstate Highway System around 1957, I-115's construction was funded by the federal government.{{cite web |first= Tony |last= DeSimone |date= October 31, 2002 |url= https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/?redirect |title=Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System Of Interstate and Defense Highways as of October 31, 2002 |work= Route Log and Finder List |publisher= Federal Highway Administration |access-date= December 20, 2013 |oclc= 47914009}}{{#tag:ref|I-115 was constructed and included in the Interstate Highway System before 1978. The Surface Transportation Assistance Act of 1978 provided that all Interstate construction authorized under previous amendments to the system would be funded by the federal government but additional highway mileage added under {{usc|23|103(c)(4)(A)}} would not be supported by the same allocation of funds.{{cite conference |author= United States Congress |authorlink= United States Congress |year= 1978 |title= Surface Transportation Assistance Act of 1978 |id= {{USPL|99|599}} }}{{cite web |first= Tony |last= DeSimone |date= June 4, 2012 |url= https://www.fhwa.dot.gov/planning/national_highway_system/interstate_highway_system/routefinder/?redirect |work= Route Log and Finder List |title= Expansion of Mileage |publisher=Federal Highway Administration |access-date= December 20, 2013 |oclc= 47914009}}|group=lower-alpha}}

Exit list

{{Jcttop|exit|state=MT|county=Silver Bow|location=Butte|length_ref={{cite report|author=Montana Department of Transportation|publisher=Montana Department of Transportation|author-link = Montana Department of Transportation |url=http://www.mdt.mt.gov/publications/docs/brochures/2011_roadlog.pdf |format=PDF|title=Montana Road Log|year=2011 |edition=2011 |accessdate=December 21, 2013}}}}

{{MTint|exit

|type=incomplete

|mile=0.000

|exit=

|road={{Jct|state=MT|I|15|dir1=South|I|90|dir2=West|BL|15|dir3=begins|BL|90|dir4=begins|dab3=Butte|dab4=Butte|city1=Billings|city2=Helena|location3=Idaho Falls|city4=Missoula}}

|notes=Exit 124 on I-15/I-90; no access to I-15 north/I-90 east}}

{{MTint|exit

|mile=1.194

|mspan=2

|exit=1

|road=Excelsior Avenue – Walkerville}}

{{MTint|exit

|exit=

|mile=none

|road={{Jct|state=MT|BL|15|dab1=Butte|dir1=North|BL|90|dab2=Butte|dir2=East|name2=Iron Street}}

|notes=Continuation beyond Excelsior Avenue}}