Interstate 15 in Nevada
|Las Vegas Freeway|
I-15 highlighted in red
|Maintained by NDOT|
|Length||123.762 mi  (199.176 km)|
|Existed||June 29, 1956–present|
|South end||I-15 at California state line|
|North end||I-15 at Arizona state line|
Interstate 15 (I-15) is an Interstate Highway in the U.S. state of Nevada that begins in Primm, continues through Las Vegas and it crosses the border with Arizona in Mesquite. Within the state, the freeway runs entirely in Clark County. Many motorists use I-15 to visit Las Vegas, as it is the only primary Interstate Highway in the city. The highway was built along the corridor of the older U.S. Route 91 (US 91) and Arrowhead Trail, eventually replacing both of these roads.
The entire route of I-15 is also part of the Las Vegas Freeway. 
Motorists in California leave the mountainous Mojave Desert and begin a long descent through Ivanpah Valley and Ivanpah Dry Lake. I-15 crosses the Nevada state line at the first exit, Primm. Once I-15 leaves Primm, the route travels north through the desert with few services. The highway then enters the Las Vegas urban area upon passing the State Route 146 (SR 146, Saint Rose Parkway) interchange. Quickly thereafter, the Interstate meets I-215 at the Southern Beltway Interchange, which provides access to Henderson and McCarran International Airport. Originally, this interchange was termed Son of Spaghetti Bowl by the Las Vegas Review-Journal when it was built.[ citation needed]
I-15 travels along the west side of the Las Vegas Strip corridor and just west of downtown Las Vegas just before its junction with I-515 and US 95 (the " Spaghetti Bowl" interchange). Then the interstate enters North Las Vegas and continues to run roughly parallel to Las Vegas Boulevard (old US 91) as it leaves the Las Vegas urban limits near the northern junction with the Clark County 215 beltway. 
Once I-15 leaves North Las Vegas, the freeway travels northeast and crosses the Muddy River at Glendale and then climbs up onto the Mormon Mesa. At Mesquite, the freeway then crosses the Arizona state line and cuts through the extreme northwestern corner of Arizona through the Virgin River Gorge before entering Utah.
The general location of the I-15 corridor through Nevada can be traced as far back as the early 1900s. Regular automobile travel through southern Nevada was established by 1914 along the Arrowhead Trail, a road connecting Los Angeles and Salt Lake City.  In 1919, the Nevada Legislature amended its newly adopted highway law to add SR 6, which was described as "Commencing at the Arizona line near Mesquite and running southwesterly over what is now known as the Arrow Head [sic] trail through Las Vegas to Jean, Nevada."  Two years later, the route was revised to pass through Las Vegas and head "via Jean or Goodsprings to a junction with the California state highway system." 
US 91 was later proposed as part of the original 1925 U.S. Highway System plan. As originally proposed, US 91 would have followed SR 6 southwest from Mesquite to downtown Las Vegas, where it would then turn southeast along SR 5 to California via Searchlight.[ citation needed] The revised 1926 plan had proposed US 91 follow SR 6 through Las Vegas and Jean to the California state line.[ citation needed] Nevada's 1927 official highway map reflects the routing of the final 1926 plan; however, a few maps from the era indicate the original proposal.  
US 91/SR 6 began at Primm and followed the Los Angeles Highway towards Las Vegas. Within the city limits, it ran along Fifth Street (now Las Vegas Boulevard) through downtown and into North Las Vegas, where it departed from 5th at Main Street. Exiting the Las Vegas area to the northeast, US 91 became the Salt Lake Highway and then headed towards Apex and Glendale. The highway then curved east-northeast before following present-day SR 170 through Riverside and Bunkerville into Mesquite. US 91 was routed through that city on Mesquite Boulevard, Sandhill Boulevard and Fairview Avenue before crossing the Arizona state line. By 1929, the alignment of US 91/SR 6 was graded throughout much of the state, a distance of 129.5 miles (208.4 km). 
The route eventually gained two other highway overlaps. US 466 was christened in 1934, and was routed concurrently along US 91 from California to downtown Las Vegas before heading southeast to Hoover Dam (the route was deleted in 1971).  Also, in 1936, US 93 was extended from its 1932 southern terminus at Glendale, over US 91 to downtown Las Vegas on its way to Hoover Dam. 
A new alignment of US 91 was completed in 1955. This bypassed both Bunkerville and Mesquite to the northwest, along what would become the future path of I-15.  The original alignment through Bunkerville is now SR 170.
The passage of the Federal Aid Highway Act of 1956 quickly brought upgrades to the US 91 corridor. The first section of the newly designated I-15 opened by 1960. This stretch extended from the California state line to just north of Sloan.  In 1963, the new freeway reached the south end of the Las Vegas Valley at Blue Diamond Road, and more than 20 miles (32 km) south of Glendale was also finished.  By 1967, I-15 had been constructed along the entire length of US 91 except through parts of Las Vegas and near Mesquite. 
The final sections of I-15 to be completed were in North Las Vegas and near the Arizona state line.  Both of these sections were completed in 1974. The US 91 designation, which had remained on its original alignment during the construction of the Interstate, was made redundant by the new freeway and was removed in 1974. 
Between Las Vegas and the Nevada state line, the Nevada Department of Transportation (NDOT) added call boxes at one-mile (1.6 km) intervals in the mid-2000s, used for motorists who end up with vehicle problems and don't have access to a cell phone or have coverage signal problems. This was done as part of a larger project that expanded this portion of the freeway to three travel lanes in each direction to coordinate with a similar effort in California.
Due to heavy traffic, there are plans by the California Department of Transportation (Caltrans) and NDOT to widen I-15 in both directions from both US 395 in Hesperia and I-40 in Barstow to I-215 in Enterprise.   
The entire route is in Clark County.
|Primm||0.00||0.00||—||I-15 south (Barstow Freeway, Mojave Freeway) – San Bernardino, Los Angeles||Continuation into California; former US 91 south/ US 466 west|
|0.39||0.63||1||Primm (Primm Boulevard)|
|Jean||12.63||20.33||12||SR 161 west (Goodsprings Road) – Jean, Goodsprings|
|Enterprise||25.52||41.07||25||Sloan (Sloan Road)||Former SR 739 east|
|27||SR 146 east (Saint Rose Parkway) / Southern Highlands Parkway – Henderson, Lake Mead|
|31||Silverado Ranch Boulevard||Southern end of I-15 HOV lanes|
|33.55||53.99||33||SR 160 (Blue Diamond Road) – Pahrump|
|34.85||56.09||34||I‑215 east / CC 215 west / Las Vegas Boulevard – McCarran Airport, Henderson||Northbound exit is part of exit 33; southbound exit to CC 215 west is part of exit 36; future I-215 west; I-215 exit 12|
|Paradise||36.39||58.56||36||Russell Road||Signed as exit 35 northbound; northbound also includes exit to Frank Sinatra Drive; former SR 594|
|37.40||60.19||37||Tropicana Avenue (SR 593)||Signed as exit 36 northbound; northbound also includes exit to Frank Sinatra Drive|
|38.35||61.72||38||Flamingo Road (SR 592 west)||Signed as exits 38A (west) and 38B (east) southbound|
|39.16||63.02||39||Spring Mountain Road||Former SR 591|
|Las Vegas||40.55||65.26||40||Sahara Avenue||Former SR 589|
|—||Neon Gateway (Western Avenue)||HOV interchange|
|41.75||67.19||41||SR 159 (Charleston Boulevard)||Northbound ramps also include access to Alta Drive, Bonneville Avenue and Grand Central Parkway; serves University Medical Center of Southern Nevada and Valley Hospital Medical Center|
|42.89||69.02||42||I‑515 south / US 93 south / US 95 / Martin L. King Boulevard – Downtown Las Vegas, Phoenix, Reno||Northern end of I-15 HOV lanes; southern end of US 93 concurrency; HOV access to US 95 north; signed as exits 42A (north) and 42B (south) northbound; I-515/US 95 exit 76|
|43||D Street, City Parkway, Washington Avenue ( SR 578 east)||Signed as exit 44 southbound|
|North Las Vegas||44.72||71.97||45||Lake Mead Boulevard ( SR 147 east)||Serves North Vista Hospital|
|46.45||74.75||46||Cheyenne Avenue ( SR 574)|
|48.44||77.96||48||Craig Road ( SR 573)|
|50.15||80.71||50||Lamb Boulevard ( SR 610 south)|
|52||CC 215 west / Tropical Parkway||No southbound exit to Tropical Parkway; interchange upgrade under construction; future I-215 west |
|53.65||86.34||54||Speedway Boulevard, Hollywood Boulevard|
|58.16||93.60||58||SR 604 south ( Las Vegas Boulevard) – Apex, Nellis AFB||Former US 91/US 93|
|64.31||103.50||64||US 93 north (Great Basin Highway) – Ely||Northern end of US 93 concurrency; Diverging diamond interchange  |
|Crystal– Moapa River Indian Reservation line||75.70||121.83||75||Valley of Fire, Lake Mead (Valley of Fire Highway)|
|Moapa River Indian Reservation||80.78||130.00||80||Ute|
|||88.71||142.76||88||Hidden Valley (Hidden Valley Road)|
|Glendale– Moapa line||90.86||146.22||90||SR 168 west (Glendale–Moapa Road) – Glendale, Moapa||Northbound exit and southbound entrance; SR 168 west was former US 93 north|
|91.63||147.46||91||Glendale, Moapa (Glendale Boulevard, Lewis Ranch Road)||No southbound entrance|
|Moapa Valley||93.91||151.13||93||SR 169 south (Moapa Valley Boulevard) – Logandale, Overton|
|||100.45||161.66||100||Carp, Elgin (Carp–Elgin Road)|
|Mesquite||112.03||180.29||112||SR 170 east (Riverside Road) – Riverside, Bunkerville||SR 170 east was former US 91 north|
|118||Lower Flat Top Drive|
|120.37||193.72||120||Falcon Ridge Parkway, Mesquite Boulevard||Dumbbell interchange; Mesquite Boulevard was former I-15 Bus. north/ SR 144 north|
|122.92||197.82||122||Pioneer Boulevard, Sandhill Boulevard||Sandhill Boulevard was former I-15 Bus. south/ SR 144 south|
|123.77||199.19||—||I-15 north (Veterans Memorial Highway) – Salt Lake City||Continuation into Arizona|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi|
- Nevada Department of Transportation (January 2019). "State Maintained Highways of Nevada: Descriptions and Maps". Retrieved February 18, 2019.
- McCabe, Francis (July 2, 2009). "Interstate 15 Projects Pile Up". Las Vegas Review Journal.
- "Arrowhead Trail (1914-1924)". State Historic Preservation. Nevada Department of Cultural Affairs. 2008. Archived from the original on December 22, 2015. Retrieved June 7, 2009.
- Statutes of the State of Nevada Passed at the Twenty-Ninth Session of the Legislature. Carson City, NV: State Printing Office. 1919. pp. 23–24. Retrieved June 2, 2009.
- Statutes of the State of Nevada Passed at the Thirtieth Session of the Legislature. Carson City, NV: State Printing Office. 1921. pp. 383–384. Retrieved June 2, 2009.
- Highway Map of the State of Nevada (Map). 1 in=25 mi. Nevada Department of Highways. 1927. Archived from the original on March 4, 2016. Retrieved June 3, 2009.
- Rand McNally Junior Auto Map (Map). Rand McNally and Co. 1927.
- Highway Map State of Nevada (Map). 1 in=25 mi. Nevada Department of Highways. 1929. Archived from the original on August 27, 2016. Retrieved June 3, 2009.
- Official Road Map of Nevada (Map). Nevada State Highway Department. 1934. Archived from the original on March 4, 2016. Retrieved June 3, 2009.
- Official Road Map of the State of Nevada (Map). Nevada Department of Highways. 1939. Archived from the original on December 26, 2014. Retrieved June 3, 2009.
- Official Highway Map of Nevada (Map). Nevada Department of Highways. 1955. Archived from the original on March 4, 2016. Retrieved June 3, 2009.
- 1960 Official Highway Map of Nevada (Map). Nevada State Highway Department. 1960. Archived from the original on January 17, 2016. Retrieved June 3, 2009.
- 1963-1964 Official Highway Map of Nevada (Map). Nevada State Highway Department. 1963. Archived from the original on February 2, 2015. Retrieved June 3, 2009.
- 1967 Official Highway Map of Nevada (Map). Nevada State Highway Department. 1967. Archived from the original on July 10, 2015. Retrieved June 3, 2009.
- 1973 Official Highway Map of Nevada (Map). Nevada State Highway Department. 1973. Archived from the original on February 2, 2015. Retrieved June 3, 2009.
- 1975 Official Highway Map of Nevada (Map). Nevada State Highway Department. 1975. Archived from the original on March 4, 2016. Retrieved June 3, 2009.
- "Mayors' wish list: Widen I-15 between Barstow and Primm". Las Vegas Review-Journal. July 10, 2017.
- "Las Vegas mayor pushing to widen I-15 between Primm, Barstow". Las Vegas Review-Journal. October 23, 2017.
- "Nevada, California officials may study widening stretch of I-15". Las Vegas Review-Journal. December 15, 2017.
- Nevada Interchanges & Structures: I-15. Nevada Department of Transportation. January 1998.
- "I-15/CC-215 Northern Beltway Interchange". Nevada Department of Transportation.
- Akers, Mick (January 2, 2018). "$58 million freeway enhancement planned for NLV near Apex - Las Vegas Sun Newspaper". lasvegassun.com.
- "New interchange opens to traffic on I-15 in North Las Vegas". Las Vegas Review-Journal. December 14, 2018.
|Wikimedia Commons has media related to Interstate 15 in Nevada.|