Interstate 15
Template:Routeboxint Interstate 15 (abbreviated I-15) is the fourth longest north-south transcontinental interstate highway in the United States, traveling through the states of Montana, Idaho, Utah, Arizona, Nevada, and California. In California, this freeway is a major transportation corridor linking the San Diego-Carlsbad-San Marcos Metropolitan area with the Riverside-San Bernardino-Ontario Metropolitan area, and various suburban communities between them. It is also the main artery of transportation through the Salt Lake City Metropolitan area. It also serves as the primary access route from Southern California to Las Vegas, Nevada, a major travel/tourist destination throughout the year. More recently, I-15 has begun to serve as a heavily traveled commuter route between the Mojave Desert communities of Victorville, Hesperia, Apple Valley, and Adelanto in California, due to rapid population growth and associated residential, commercial, and industrial development.
The I-15 corridor between Los Angeles and Las Vegas has long been proposed as a maglev train route; in 2004 the California-Nevada Interstate Maglev project held public meetings on the plan. [1]
Route Summary
This highway's beginning is in San Diego, California at the Interstate 8 merge, 18 miles north of the international border with Mexico. However, work is being done to extend this to Interstate 5 (the current work on this extension is signed California State Highway 15). The northern terminus is in Sweetgrass, Montana at the international border between the United States and Canada, where it becomes Alberta provincial highway 4.
California
North of its junction with the Riverside Freeway, California State Route 91 (CA/SR-91), in the Inland Empire near Corona, the route follows (roughly) the old U.S. Highway 91. North of Devore, California the highway follows the approximate alignment of historic U.S. Highway 66 until about the Mojave River 35 miles (56 km) to the north.
Interestingly, the starting point of Interstate 15 was originally planned to be in San Bernardino at an interchange with the San Bernardino Freeway, Interstate 10 (I-10). This was logical as I-15 was following the old alignment of the historic route U.S. Route 66 which passed through San Bernardino. The segment was completed accordingly. However, legislation was later passed to extend the interstate to San Diego. But instead of extending the existing freeway from the I-10 interchange south, the California Department of Transportation created a new segment in Devore that 'branched' off of the original alignment and bypassed San Bernardino altogether. This segment's alignment is generally northeast to southwest for about 15 miles (24 km). Then, in Fontana/Rancho Cucamonga, California, its directional alignment shifts to north-south where it eventually junctions with Interstate 10 (about 15 miles west of the original interchange in San Bernardino). The segment that had been built from Devore to San Bernardino was retained as an interstate, but was re-numbered as Interstate 215. Note that during the construction of I-15's present alignment, and for some time afterwards, I-215 was numbered as I-15E.
There are three bypasses and loops identified as Interstate 215: in the Inland Empire region of California, Las Vegas, and Salt Lake City.
In California, I-15 has at least five different names throughout its length. From its beginning to the Riverside/San Diego county line, it is named the Escondido Freeway. The portion of the Escondido Freeway passing through the Marine Corps Air Station at Miramar is also known as the Semper Fi Highway. From the San Diego county line to California State Route 74 (the Ortega Highway) in Lake Elsinore, it is named the Temecula Valley Freeway. From CA/SR-74 to Limonite Avenue in Riverside County, it is known as the Corona Freeway. From Limonite Avenue to the northern junction with I-215 spur in Devore, it is named the Ontario Freeway. From the northern I-215 junction to the Interstate 40 junction in Barstow, California, it is named the Barstow Freeway. Finally, from Barstow to the California/Nevada state line it is named the Mojave Freeway.
State Law
Legal Definition of Route 15: California Streets and Highways Code, Chapter 2, Article 3, Section 315 Template:CAFES Template:CAScenicAlt
Nevada
Interstate 15 in Nevada begins in Primm at the California Border. It continues on through the Las Vegas, intersecting with I-215 and I-515 or "The Spaghetti Bowl." After Vegas traffic is much less congested. I-15 continues up to Mesquite, Nevada on the Arizona state line.
Arizona
I-15 just clips the northwestern corner of Arizona with a total mileage of less than 30. The stretch is separated from the rest of the state and has no major exits or junctions.
Utah
I-15 continues through Utah with a mileage of just over 400. It is the main north-south connection for the state. The highway passes through St. George, Cedar City, Spanish Fork, Provo, Orem, American Fork, Lehi, Sandy, Salt Lake City, Ogden, and finally Brigham City. The freeway also intersects with I-70, I-215, and merges with I-80, and I-84 (Western).
Idaho
I-15 passes through Idaho for nearly 200 miles. The highway runs through Pocatello, Blackfoot, and Idaho Falls. It also merges with Interstate 86.
Montana
Interstate 15 continues onward through nearly 400 miles of Montana through the cities of Butte, Helena and Great Falls, intersecting with Interstate 90, Interstate 115 and Interstate 315. Interstate 15 reaches its northern termninus at the International Border with Alberta, Canada.
Length
Miles | km | state | |
292 | 473 | California | |
124 | 201 | Nevada | |
29.40 | 47 | Arizona | |
401 | 650 | Utah | |
196 | 318 | Idaho | |
396 | 642 | Montana | |
1,433.52 | 2,307 | Total |
Major cities
Bolded cities are officially-designated control cities for signs.
- San Diego, California
- Riverside, California
- San Bernardino, California
- Los Angeles, California (via Interstate 10)
- Barstow, California
- Las Vegas, Nevada
- Saint George, Utah
- Provo, Utah
- Salt Lake City, Utah
- Ogden, Utah
- Pocatello, Idaho
- Idaho Falls, Idaho
- Butte, Montana
- Helena, Montana
- Great Falls, Montana
Major intersecting freeways and highways
Listed in order from south to north:
California
- File:Interstate 8.svg Mission Valley Freeway in San Diego at 32° 46' 43"N, 117° 06' 45"W
- File:CA-52.gif Soledad Freeway in Miramar at 32° 50' 30"N, 117° 07' 14"W
- File:CA-163.gif Cabrillo Freeway in Miramar at 32° 51' 33"N, 117° 06' 48"W
- File:CA-56.gif Ted Williams Freeway near Poway at 32° 57' 53"N, 117° 05' 44"W
- File:CA-78.gif Vista Freeway in Escondido at 33° 07' 38"N, 117° 06' 18"W
- File:US 395.gif Old Highway 395 near Rainbow Pass
- File:CA-76.gif (surface street) near Fallbrook
- File:CA-79.gif Winchester Road (surface street) in Temecula
- File:Interstate 215.svg Escondido Freeway in Murietta at 33° 32' 53"N, 117° 10' 50"W
- File:CA-74.gif Ortega Highway (surface street) in Lake Elsinore
- File:CA-91.gif Riverside Freeway in Corona at 33° 52' 54"N, 117° 32' 52"W
- File:CA-60.gif Pomona Freeway in unincorporated Riverside County at 34° 01' 18"N, 117° 33' 01"W
- File:Interstate 10.svg San Bernardino Freeway in Ontario at 34° 04' 03"N, 117° 32' 42"W
- File:CA-66.gif Foothill Boulevard (surface street) in Rancho Cucamonga
- File:CA-210.gif Foothill Freeway in Rancho Cucamonga at 34° 08' 09"N, 117° 29' 48"W
- File:Interstate 215.svg Barstow Freeway in Devore at 34° 13' 31"N, 117° 24' 35"W
- File:CA-138.gif Antelope Highway (surface street) in unincorporated San Bernardino County
- File:US 395.gif (surface street) south of Hesperia
- File:CA-18.gif Palmdale Road/D Street (surface streets) in Victorville
- File:CA-58.gif south of Barstow at 34° 52' 14"N, 117° 04' 36"W
- File:CA-247.gif Barstow Road (surface street) in Barstow
- File:Interstate 40.svg in Barstow at 34° 53' 11"N, 117° 00' 36"W
- File:CA-127.gif Kelbaker Road (surface street) in Baker
Nevada
- File:Interstate 215.svg in unincorporated Clark County (Paradise) near McCarran International Airport
- File:Interstate 515.svg in Las Vegas
Arizona
Interstate 15 does not intersect any major roads in Arizona.
Utah
- File:Interstate 70.svg in Cove Fort
- File:Interstate 215.svg in Murray
- File:Interstate 80.svg in South Salt Lake; they merge for about 3 mi (5 km) into Salt Lake City
- File:Ut201.GIF in South Salt Lake
- File:Interstate 215.svg in North Salt Lake
- File:Interstate 84.svg in Ogden; they stay merged until Tremonton
Idaho
Montana
- File:Interstate 90.svg in Butte; they are merged for 9 miles (14.5 km)
Spur routes
- Inland Empire, California - I-215
- Spur to Henderson, Nevada outside Las Vegas - I-515
- Beltway Las Vegas, Nevada - I-215
- Salt Lake City, Utah - I-215
- Butte, Montana - I-115
- Great Falls, Montana - I-315
Notes
- Managed Lanes Project- Initated during fall 2003 and will finish late 2007. Portion of CA-56 to Centre City Pkwy (former US 395). More info in "reference" section; See also high occupancy toll.
- At the time it was built, the section running through the northwest corner of Arizona (the Virgin River gorge) was the most expensive section (per mile) of the entire interstate system.
- The sign for the Zzyzx exit, the alphabetically last place name in the United States, is a well-known landmark along the drive from Los Angeles to Las Vegas on I-15.
- Interstate 15 had an eastern branch bypassing San Bernardino, California, and a western branch in Idaho. I-215 around San Bernardino was I-15E, and the western I-86 was once called I-15W.
- The eastern section of I-215 in Salt Lake City, from the south interchange with I-15 east to I-80, was once known as I-415.
- I-15 ends at the border between Montana and Alberta, where it becomes Alberta provincial highway 4. Combined with Alberta provincial highway 3 and Alberta provincial highway 2, this route can be used to go into the cities of Calgary and Edmonton and other Alberta cities.
Reference and External links
- http://www.ihoz.com/interstates.html
- http://www.dot.ca.gov/dist11/facts/I-15managed.pdf
- 2005 Rand McNally "The Road Atlas 2005" - newest feature- interstate mileage by state
California
- California Highways: CA-15
- The Big Highways Page: California Route 15
- Western Exit Guide - Interstate 15 California
- Cal-NExUS: Route 15 North
- Cal-NExUS: Route 15 South
Arizona
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