Interstate 15 in Utah

This article is about the section of this freeway in Utah. For the entire length of the freeway, see Interstate 15.

Interstate 15
Route information
Defined by Utah Code §72-4-107
Maintained by Utah Department of Transportation (UDOT)
Length:	400.592 mi (644.690 km)
Major junctions
South end:	I-15 towards Littlefield, Arizona
	I-70 near Cove Fort US-50 near Holden US-6 in Santaquin I-215 in Murray and North Salt Lake I-80 in Salt Lake City I-84 in Riverdale US-91 in Brigham City I-84 in Tremonton
North end:	I-15 towards Malad, Idaho
Highway system
Interstate Highway System Main Auxiliary Business State highways in Utah Interstate • US State (Parks) Scenic ← SR-14 SR-16 →

In the U.S. state of Utah Interstate 15 runs north–south through the southwestern and central portions of the state, passing through many of the population centers of that state, including St. George, Provo, Salt Lake City, and Ogden, the latter three being part of the urban area known as the Wasatch Front. It is the primary north–south highway in Utah, as the majority of the state's population lives along its corridor. The only Metropolitan Statistical Area in Utah not connected via I-15 is the Logan Utah-Idaho Metropolitan Statistical Area.

Route description

The interstate passes through the fast-growing Dixie region, which includes St. George, Cedar City, and eventually most of the major cities and suburbs along the Wasatch Front, including Provo, Orem, Sandy, West Jordan, Salt Lake City, Layton, and Ogden. Around Cove Fort, Interstate 70 begins its journey eastward across the country. The interstate merges with I-80 for about 3 miles (4.8 km) from South Salt Lake to just west of Downtown Salt Lake City and also merges with Interstate 84 from Ogden to Tremonton. Along nearly its entire length through the state, I-15 winds its way along the western edge of a nearly continuous range of mountains (the Wasatch Range in the northern half of the state). The only exceptions are when it passes through the mountains south of Cedar City and again north of Cove Fort.

Extinct volcano cone near Fillmore, Utah off I-15.

I-15 begins at the Arizona/Utah border and heads northeast, continuing with two lanes in each direction. Right past the border, there is a port of entry on each side, making the first exit on the interstate in Utah going northbound. The route turns north past Bloomington before turning northeast again after the interchange with SR-18 to pass the eastern side of St. George. The highway continues northeast after exiting St. George and turns north-northeast north of Toquerville. South of Cedar City, the route turns east and north to pass through the west side of Cedar City and turns northeast again. Past a ranch exit (exit 100), the interstate turns northwest and then north to enter the western side of Beaver, with two interchanges serving that town. The road continues in a general north-northeast direction before intersecting with the western terminus of I-70. Past I-70, the route meanders to the north and northeast before straightening out to the northeast southwest of Kanosh. The highway passes the east side of both Meadow and Fillmore and the west side of Holden. The route turns north briefly after bypassing Scipio to the east before turning northeast. Past the interchange with SR-28 (which serves as a connector to I-70 for southbound I-15 motorists), the road passes the eastern side of Nephi. The interstate then turns northwest and north, bypassing Mona and Rocky Ridge to the east.

Interstate 15 near New Harmony, south of Cedar City, looking north.

The highway enters the Wasatch Front and the Provo-Orem metropolitan area as it turns northeast and enters the town of Santaquin, where US-6 begins its overlap with I-15. Exiting Santaquin, the highway turns north and then northeast again to enter Payson. Continuing northeast, the route enters Spanish Fork and gains one lane in each direction (the first time the interstate widens in the state). On the north side of Spanish Fork it intersects with US-6, where it turns north and gains one more lane in each direction, plus an additional [High occupancy/toll and express toll lanes|express lane]] in both directions. This interchange also marks the northern end of the overlap with US-6. (The section between Spanish Fork and Lehi was recently rebuilt in 2010-12 as part of the I-15 CORE project.) Continuing north with four lanes, plus an Express Lane, in both directions, the route passes through the far west side of Springville, crossing SR-77 and SR-75, and then turns northwest south of Provo. The highway enters Provo and intersects with the southern terminus of US-189. The route continues northwest, bisecting the west side of Provo. After passing SR-114, it reaches Orem and passes SR-265. Right before the interchange at SR-241, the route turns northwest, entering Lindon. The route then exits Lindon and enters the south side American Fork, meandering between the west-northwest and northwest. The route straightens out the northwest and enters Lehi. In Lehi, US-89 begins an overlap with I-15 and passes SR-92. At this point the freeway narrows to just three lanes, plus and Express Lane, in both directions. Past Lehi, the interstate exits the Provo metropolitan area and Utah County to enter the Salt Lake City metropolitan area.

I-15 in Salt Lake City

As the route enters the Salt Lake Valley from only one of three other points connecting Salt Lake County and Utah County (the others being SR-68 and Traverse Ridge Road), it turns northeast. Past SR-140 turns north. The route enters Draper and turns north-northwest past SR-71, where US-89 ends its overlap with the interstate. As it enters Sandy, the interstate widens to five lanes past SR-151. The route straightens out to the north. The route turns north-northwest past SR-209 and soon after enters Midvale. The route intersects I-215, a beltway running through many of Salt Lake City's suburbs, in Murray. Past this interchange, the route heads north and enters Murray. The route exits Murray and enters South Salt Lake, where an interchange with I-80 and SR-201 is located. The southern overlap of I-80 begins at this point. Also at this point, the highway enters Salt Lake City and a collector/distributor road begins at either side of the interstate, providing an exit to SR-201, 1300 South, and SR-270. After the collector-distributor ends, the route turns northwest to bypass downtown Salt Lake City. The route turns north after SR-269 and the northern end of the I-80 overlap. Past this point, the HOV lane ends and the highway loses one lane in each direction. Past the single-point urban interchange at SR-268, the interstate turns northwest and loses another lane. Before US-89], the road turns northeast briefly before turning north and entering Davis County.

An 80 mph speed limit sign in one of the test zones.

The road enters North Salt Lake and I-215 defaults onto I-15 northbound. The route then gains two lanes in each direction and turns northeast. Past 2600 South, the highway turns north and enters Woods Cross to the west and Bountiful to the east. In West Bountiful, US-89 begins another overlap with I-15. The highway continues north and enters Centerville. The route exits Centerville and enters Farmington and turns northwest, US-89 exiting on its own separate freeway at an interchange (where the Legacy Parkway terminates). The route passes through Kaysville, Layton, and Clearfield before turning north, passing the west side of Hill Air Force Base. The road continues north through Sunset before turning northeast through Roy. The interstate exits Davis County and enters Weber County. In Roy, I-84 defaults onto I-15 northbound and an overlap begins. The highway enters Ogden and the Ogden-Hinckley Airport is located on the west side of the highway. Past the airport, the route turns northwest before exiting Ogden and entering Marriott-Slaterville, where it straightens out to the north. Past Farr West, the highway turns northwest briefly before turning north and exiting Weber County, the Ogden-Clearfield metropolitan area, and the Wasatch Front.

I-15 warning sign for potentially drowsy drivers

The interstate continues north through Box Elder County. Brigham City, the county seat, is bypassed to the west by the freeway. Past US-91 (which continues to Logan and points northward), the route turns northwest to Tremonton, where I-84 separates, continuing northwest, and I-15 turns north. The freeway continues in this general direction until the Idaho border. The last exit northbound is located at exit 398, 25800 North, which provides a connection to the town of Portage.

History

See also: U.S. Route 91

The southwest-north alignment followed by I-15 was a major transportation corridor in the early 20th century, followed by auto trails such as the Arrowhead Trail (south from Salt Lake City), Evergreen National Highway (entire length), and Banff-Grand Canyon Road (north from Nephi). In 1926, when the numbered system of U.S. highways was created, this route was signed U.S. Route 91

Legislative designation for I-15 within Utah, until 1977

The route of I-15 from St. George to Brigham City was built along the corridor of what was U.S. Route 91 from 1926-1974. In 1974 I-15 was reasonably intact and US-91 was deleted, with the unfinished segments signed as Temporary I-15. The route north of Brigham City was built along the corridor of an old route of U.S. Route 191. This highway was also deleted once I-15 was reasonably intact. However, a different route in Utah was re-designated US-191 in 1982.

Prior to 1977 the route of I-15 (and US-91 before) was also designated State Route 1 by the state of Utah, but no portion of the route was signed with this number.

In January 2009, the speed limit on two sections of I-15 together totaling 34 miles was raised to 80 mph as a "test," making Utah the second state to currently have speed limits greater than 75 mph. Since that time additional sections with higher speed limits have been added within Utah.

Exit list

County	Location	Mile	km	Old exit	New exit	Destinations	Notes
Washington	St. George	2.135	3.436	2	2	SR-7 (Southern Parkway)
		4.641	7.469	4	4	Brigham Road
		6.309	10.153	6	6	SR-18 / I-15 Bus. north (Bluff Street)
		8.652	13.924	8	8	I-15 Bus. south / SR-34 (St. George Boulevard) to SR-18 – St. George, Santa Clara
	Washington	10.910	17.558	10	10	SR-212 east – Washington
		13.386	21.543	13	13	Washington Parkway
		15.888	25.569	16	16	SR-9 – Hurricane, Zion National Park
	Leeds	22.579	36.337	22	22	Leeds, Silver Reef (SR-228)	Northbound exit and southbound entrance
		23.703	38.146	23	23	Leeds, Silver Reef (SR-228)	Southbound exit and northbound entrance
	Toquerville	27.470	44.209	27	27	SR-17 – Toquerville, Hurricane
		30.682	49.378	30	30	Browse
		31.861	51.275	31	31	Pintura
		33.435	53.808	33	33	Ranch exit
		36.763	59.164	36	36	Ranch exit
		40.253	64.781	40	40	Kolob Canyons (Zion National Park)
		42.159	67.848	42	42	New Harmony, Kanarraville	Former SR-58
Iron		51.149	82.316	51	51	Hamilton Fort, Kanarraville	Former SR-58
	Cedar City	56.787	91.390	57	57	I-15 Bus. north (SR-130) to SR-14 – Cedar City
		58.837	94.689	59	59	SR-56 – Cedar City
		62.497	100.579	62	62	SR-130 (I-15 Bus. south) – Cedar City, Enoch, Minersville
		70.263	113.077	71	71	Summit, Enoch	Former SR-38
	Parowan	75.183	120.995	75	75	I-15 Bus. north / SR-143 – Parowan
		77.801	125.209	78	78	I-15 Bus. south (SR-274) to SR-143 – Parowan, Paragonah
		82.253	132.373	82	82	SR-271 – Paragonah
		94.453	152.007	95	95	SR-20 to US-89 – Panguitch, Kanab, Circleville
		99.690	160.436	100	100	Ranch exit
Beaver		108.745	175.008	109	109	I-15 Bus. north (SR-160) to SR-21 – Beaver, Milford
	Beaver	111.780	179.892	112	112	I-15 Bus. south (SR-160) to SR-21 – Beaver, Milford, Manderfield
		120.126	193.324	120	120	Manderfield
				125	125	Ranch exit	Exit closed
		129.438	208.310	129	129	Sulphurdale
Millard		132.170	212.707	132	132	I-70 east – Richfield, Denver
		134.875	217.060	135	135	Historic Cove Fort (SR-161)
		138.073	222.207	138	138	Ranch exit
		146.493	235.758	146	146	Kanosh	Former SR-133
	Meadow	158.265	254.703	158	158	SR-133 – Meadow, Kanosh
	Fillmore	163.370	262.919	163	163	I-15 Bus. north (SR-99) – Fillmore
		166.723	268.315	167	167	I-15 Bus. south (SR-99) – Fillmore
		173.507	279.232	174	174	SR-64 north to US-50 west – Holden, Delta
		178.330	286.994	178	178	US-50 west – Holden, Delta	South end of US-50 overlap
		183.638	295.537	184	184	Ranch exit
		188.439	303.263	188	188	US-50 east – Scipio	North end of US-50 overlap
Juab		202.189	325.392	202	202	Yuba State Park
		206.553	332.415	207	207	Mills, Levan (SR-78)
	Nephi	222.812	358.581	222	222	I-15 Bus. north / SR-28 to I-70 – Nephi, Salina, Richfield
		225.266	362.530	225	225	SR-132 – Nephi, Manti
		228.091	367.077	228	228	I-15 Bus. south (SR-28) – Nephi, Delta
		233.161	375.236	233	233	SR-54 – Mona
Utah	Santaquin	242.447	390.181	245	242	South Santaquin
		244.809	393.982	248	244	US-6 west – Santaquin, Delta	South end of US-6 overlap
	Payson	248.845	400.477	252	248	Payson, Salem (SR-178)
		250.923	403.821	254	250	SR-115 – Payson, Benjamin
		253.557	408.060	256	253	SR-164 – Spanish Fork, Benjamin
	Spanish Fork	257.264	414.026	260	257	SR-156 – Spanish Fork
		257.636	414.625	261	258	US-6 east to US-89 – Price, Manti	North end of US-6 overlap; northbound exit is via exit 257
	Springville	259.976	418.391	263	260	SR-77 – Springville
		261.821	421.360	265	261	SR-75 – Springville, Provo
	Provo	263.373	423.858	266	263	US-189 north (University Avenue) / 1860 South
		265.589	427.424	268	265	SR-114 (Center Street) – Provo, Provo Municipal Airport	Signed as exits 265A (east) and 265B (west) northbound
	Orem	269.072	433.029	272	269	SR-265 (University Parkway)
		270.660	435.585	274	271	Center Street – Orem
		271.670	437.210	275	272	SR-52 (800 North) to US-189
	Lindon	272.767	438.976	276	273	1600 North (SR-241) – Lindon
	Pleasant Grove	275.328	443.097	278	275	Pleasant Grove, Lindon	Near the Sam White Bridge
	American Fork	276.501	444.985	279	276	500 East (SR-180) – American Fork, Pleasant Grove
		278.586	448.341	281	278	Main Street (SR-145) – American Fork
	Lehi	279.701	450.135	282	279	SR-73 west (Main Street) – Lehi
		282.311	454.336	285	282	US-89 south / 1200 West – Lehi	South end of US-89 overlap
		283.985	457.030	287	284	SR-92 – Highland, Alpine
Salt Lake	Draper	288.272	463.929	291	288	SR-140 (14600 South)
		289.832	466.439	293	289	SR-154 (Bangerter Highway)
		291.358	468.895	294	291	US-89 north / SR-71 (12300 South)	North end of US-89 overlap
	Sandy	292.612	470.913		292	SR-175 (11400 South)	Opened late 2010
		293.634	472.558	297	293	SR-151 (10600 South)
		295.616	475.748	298	295	SR-209 (9000 South)
	Midvale	297.920	479.456	301	297	SR-48 (7200 South)
	Murray	299.005	481.202	302	298	I-215 (Belt Route)
		300.300	483.286	303	300	SR-173 (5300 South)
		301.653	485.463	304	301	SR-266 (4500 South)
	South Salt Lake	303.414	488.298	306	303	SR-171 (3300 South)
		304.691	490.353	307	304	I-80 east – Cheyenne	South end of I-80 overlap Part of the "Spaghetti Bowl" interchange
		305.231	491.222	308A	305A	SR-201 west – West Valley	Part of the "Spaghetti Bowl" interchange
		305.198	491.169	308B	305B	2100 South (SR-201)
	Salt Lake City	306.315	492.966	309A	305C	1300 South
		306.607	493.436	309B	305D	900 South (SR-270)	Northbound exit and southbound entrance
		307.500	494.873	310	306	600 South (SR-269)	Northbound exit and southbound entrance
		307.740	495.260	310	307	400 South	Northbound exit and southbound entrance are HOV-only
		308.079	495.805	311	308	I-80 west – Salt Lake City International Airport, Reno	North end of I-80 overlap
		309.333	497.823	312	309	600 North (SR-268)
		310.239	499.281	313	310	1000 North	No northbound exit
		311.792	501.781	314	311	2300 North/Warm Springs Road
		311.947	502.030	315	312	US-89 south (Beck Street)	Southbound exit and northbound entrance
Davis	North Salt Lake	313.128	503.931	315	312	US-89 north	Northbound exit and southbound entrance
		313.275	504.167	316	313	I-215 south (Belt Route) – Salt Lake City International Airport	Southbound exit and northbound entrance
		314.301	505.818	317	314	Center Street	Southbound exit only
	North Salt Lake–Woods Cross line	315.243	507.334	318	315	2600 South (SR-93)
	Woods Cross–Bountiful–West Bountiful line	316.870	509.953	320	316	SR-68 (500 South)
	West Bountiful	317.557	511.058	321	317	400 North (SR-106)	Northbound exit and southbound entrance
	West Bountiful–Bountiful line	318.024	511.810	321	317	US-89 south	South end of US-89 overlap; southbound exit and northbound entrance
	Centerville	319.512	514.205	322	319	Centerville (SR-105)
	Farmington	322.916	519.683	325	322	SR-227 / Lagoon Drive – Farmington	Northbound exit and southbound entrance
		324.026	521.469	326	324	US-89 north to I-84 east – South Ogden	North end of US-89 overlap; northbound exit and southbound entrance
		324.243	521.819		324	Legacy Parkway	Southbound exit and northbound entrance
		324.741	522.620	327	325	SR-225 / Lagoon Drive – Farmington	Northbound exit is via exit 324
	Kaysville	328.640	528.895	331	328	SR-273 – Kaysville
	Layton	330.019	531.114	332	330	I-15 Bus. north / SR-126 – Layton	Northbound exit and southbound entrance
		331.589	533.641	334	331	SR-232 (Hill Field Road) – Layton
		332.883	535.723	335	332	SR-108 (Antelope Drive) – Antelope Island
	Clearfield	334.066	537.627	336	334	SR-193 (700 South)
		335.800	540.418	338	335	SR-103 (650 North)
Weber	Roy	338.447	544.678	341	338	SR-97 (5600 South)
	Riverdale	339.133	545.782	342	339	SR-26 (Riverdale Road) to I-84 east	Northbound exit and southbound entrance
		340.227	547.542	343	340	I-84 east – Riverdale, Cheyenne	South end of I-84 overlap; northbound exit is via exit 339
	Ogden	341.948	550.312	344	341	SR-79 (31st Street)
		343.067	552.113	345	342	SR-53 (24th Street)	Northbound exit and southbound entrance
	West Haven	343.852	553.376	346	343	SR-104 (21st Street, Wilson Lane) – Ogden City Center
	Marriott-Slaterville	344.968	555.172	347	344	SR-39 (12th Street)
		346.726	558.001	349	346	400 North
	Farr West	349.361	562.242	352	349	SR-134 (2700 North)
Box Elder		351.853	566.253	354	351	SR-126 to US-89 – Willard, Pleasant View
	Willard	357.554	575.427	360	357	SR-315 – Willard, Perry
		358.566	577.056	361		Port of Entry
		360.542	580.236	363		Rest Area	Northbound exit and entrance
		362.020	582.615	364	362	US-91 (1100 South Street, I-15 Bus. north, I-84 Bus. west) to US-89
	Brigham City	363.738	585.380	366	363	Forest Street
		365.508	588.228	368	365	SR-13 (900 North Street, I-15 Bus. south, I-84 Bus. east)
	Honeyville	372.734	599.857	375	372	SR-240 to SR-13 – Honeyville, Bear River
	Tremonton	376.532	605.970	379	376	SR-13 (I-15 Bus. north, I-84 Bus. west) – Tremonton, Garland, Bear River
		379.334	610.479	382	379	I-84 west (SR-30 west) – Tremonton, Boise	North end of I-84 overlap; south end of SR-30 overlap
	Tremonton	381.037	613.220	383	381	I-15 Bus. south – Tremonton, Garland
		385.266	620.026	387	385	SR-30 east – Riverside, Logan	North end of SR-30 overlap
		392.387	631.486	394	392	SR-13 south – Plymouth
		398.817	641.834	402	398	Portage	Former SR-90
Concurrency terminus       Closed/former       HOV only       Incomplete access       Tolled/ETC       Unopened

External links

Template:Attached_KML/Interstate 15 in Utah

Interstate 15
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