State Route 145 is a west–east thoroughfare completely within Utah County

Utah County, Utah

Utah County is a county located in the U.S. state of Utah. As of 2000, the population was 368,536 and by 2008 was estimated at 530,837. It was named for the Spanish name for the Ute Indians. The county seat and largest city is Provo...

 in northern Utah

Utah

Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

 that cuts through Saratoga Springs

Saratoga Springs, Utah

Saratoga Springs is a city in Utah County, Utah, United States. The elevation is 4,505 feet. It is part of the Provo–Orem, Utah Metropolitan Statistical Area. The city is a relatively new development along the northern shores of Utah Lake. It was incorporated on December 31, 1997 and has...

, Lehi

Lehi, Utah

-Attractions:Lehi Roller MillsLehi Roller Mills was founded in 1906 by a co-op of farmers. George G. Robinson purchased the mill in 1910, and since then it has remained in the family. It is run today by grandson R. Sherman Robinson....

, American Fork

American Fork, Utah

American Fork is a city in Utah County, Utah, United States, at the foot of Mount Timpanogos in the Wasatch Range, north of Utah Lake. It is part of the Provo–Orem, Utah Metropolitan Statistical Area. The population was 26,263 at the 2010 census, nearly a 20% growth since the 2000 census...

, and portions of unincorporated Utah County. While the portion between Interstate 15

Interstate 15 in Utah

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...

 (I-15) and U.S. Route 89

U.S. Route 89 in Utah

In the U.S. state of Utah, U.S. Route 89 is a long north–south state highway spanning more than through the central part of the state. Between Provo and Brigham City, US-89 serves as a local road, paralleling Interstate 15, but the portions from Arizona north to Provo and Brigham City...

 (US-89) has been under state jurisdiction since 1978, the remaining roadway between SR-68 and I-15—named Pioneer Crossing—opened in 2010, forming an alternative routing to SR-73, which also connects SR-68 and I-15 further north. The original portion of the route between I-15 and US-89 is designated as Main Street in American Fork's street grid.

Route description

Commencing from the route's western terminus in northern Saratoga Springs, SR-145 heads east as Pioneer Crossing with two lanes in each direction, divided by a center turn lane. After crossing over the Jordan River

Jordan River (Utah)

The Jordan River in the U.S. state of Utah is a river about long. Regulated by pumps at its headwaters at Utah Lake, it flows northward through the Salt Lake Valley and empties into the Great Salt Lake. Four of Utah's five largest cities—Salt Lake City, West Valley City, West Jordan and...

, the route takes a brief northeasterly turn before returning due east. The route passes through a rural area of western Utah County before entering a stretch of development past 2300 West. The highway turns southeast to avoid development before again turning northeast and east. The road gains a third lane in each direction past 300 East (on Lehi's grid) and meets I-15 at a diverging diamond interchange

Diverging diamond interchange

A diverging diamond interchange is a rare form of diamond interchange in which the two directions of traffic on the non-freeway road cross to the opposite side on both sides of the bridge at the freeway. It is unusual in that it requires traffic on the freeway overpass to briefly drive on the...

. The road continues east for about a half-mile, this time as American Fork's Main Street, and ends at an intersection with State Street (US-89).

History

State maintenance of Main Street in American Fork (from I-15 to US-89) was established in May 1978, the state legislature approving that the following year. By 2003, a concept of a Redwood Road–I-15 connector was made present in an environmental impact study for the Mountain View Corridor

Mountain View Corridor

The Mountain View Corridor, numerically designated as State Route 85 , is an expressway currently under construction that will run along the western periphery of Salt Lake County and northwest Utah County in northern Utah. A spur of the eventual freeway to Interstate 15 opened in northwestern Utah...

. After a separate study was completed in 2008, plans to construct the connector were set in place. As part of a project to reconstruct over twenty miles of I-15 through Utah County, the present interchange at Main Street was set to be rebuilt as a diverging diamond interchange. Construction began in early 2009, with the road opening to traffic in August 2010. The diverging diamond interchange was the second to be opened in the United States, the first being in Missouri

Missouri

Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...

.

Major intersections

The entire route is located in Utah County.
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