Interstate 180 (I-180) is a connector in the US state of Wyoming between I-80 and downtown Cheyenne. It is unusual for being one of the few

Interstate Highway The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. Th ...

s that does not conform to

Interstate Highway standards Standards for Interstate Highways in the United States are defined by the American Association of State Highway and Transportation Officials (AASHTO) in the publication ''A Policy on Design Standards: Interstate System''. For a certain highway to ...

. There is also no freeway anywhere along its route. Other routes in Alaska and Hawaii are similar in nature, as they are funded by Interstate dollars but do not conform to Interstate Highway standards. The only

grade separation In civil engineering (more specifically highway engineering), grade separation is a method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other tran ...

s are a diamond interchange at its southern end (at a junction with I-80) and a pair of bridges that run over 1st Street and the Union Pacific railroad tracks. However, even the interchange with I-80 is a standard diamond with signalized intersections. It is a

divided Division is one of the four basic operations of arithmetic, the ways that numbers are combined to make new numbers. The other operations are addition, subtraction, and multiplication. At an elementary level the division of two natural numb ...

at-grade

expressway Expressway may refer to: * Controlled-access highway, the highest-grade type of highway with access ramps, lane markings, etc., for high-speed traffic. * Limited-access road, a lower grade of highway or arterial road. *Expressway, the fictional s ...

with a speed limit due to the frequency of signals. There are five traffic signals along I-180. I-180 is cosigned with I-25 Business (I-25 Bus), US Highway 85 (US 85), and US 87 Bus, making it the only

concurrency Concurrent means happening at the same time. Concurrency, concurrent, or concurrence may refer to: Law * Concurrence, in jurisprudence, the need to prove both ''actus reus'' and ''mens rea'' * Concurring opinion (also called a "concurrence"), a ...

of an Interstate, Interstate business route, US Highway, and US Highway business route. It is also the only auxiliary Interstate Highway in Wyoming.

Route description

I-180 begins at a diamond interchange with I-80 in Cheyenne, heading north concurrently with I-25 Bus/ US 85/ US 87 Bus on the four-lane

North Greeley Highway. South of this interchange, I-25 Bus/US 85/US 87 Bus continue along North Greeley Highway. From the southern terminus, I-180 passes over Deming Drive and passes local homes and businesses. The road curves northwesterly and intersects 5th Street at a traffic light. The highway passes under a pedestrian bridge at 7th Street before crossing 9th Street at a signalized intersection. Past 9th Street, the directions of I-180 split and pass over a large Union Pacific Railroad yard. After this bridge, I-180 reaches its northern terminus at an at-grade signalized intersection with I-80 Bus/ US 30. Past this intersection, I-25 Bus/US 85/US 87 Bus continue north on the one-way pair of Warren Avenue northbound and Central Avenue southbound.

History

I-180 was conceived in November 1967, when Wyoming requested it for a new spur route into Cheyenne. The

American Association of State Highway Officials The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test protocols, and guidelines that are used in highway design and construction throughout the United St ...

(AASHO) added it to the Interstate Highway System in June 1970. The original plan was to have a freeway along the same corridor, with a full freeway-to-freeway interchange at I-80, but the Federal Highway Administration (FHWA) rejected it in December 1970 due to high cost and access issues. Wyoming revised the proposal to the current configuration in February 1971, and it was approved by the FHWA that March. I-180 opened in June 1984, after six years of expressway upgrades.

Major intersections

References

External links

I-180 at AARoads.com
{{3di, 80 80-1 Wyoming 80-1 1 Wyoming Transportation in Cheyenne, Wyoming Transportation in Laramie County, Wyoming