Interstate 225 (I-225) is an
auxiliary Interstate Highway
Auxiliary Interstate Highways (also called three-digit Interstate Highways) are a supplemental subset of the freeways within the Interstate Highway System of the United States.
Auxiliary routes are generally classified as spur routes, which con ...
in the U.S. state of
Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...
. The freeway is a connector
spur route
A spur route is a short road forming a branch from a longer, more important road such as a freeway, Interstate Highway, or motorway. A bypass or beltway should not be considered a true spur route as it typically reconnects with another or the s ...
of
I-25
Interstate 25 (I-25) is a major Interstate Highway in the western United States. It is primarily a north–south highway, serving as the main route through New Mexico, Colorado, and Wyoming. I-25 stretches from I-10 at Las Cruces, New Mexic ...
that acts as an eastern bypass in the
Denver metropolitan area
Denver is the central city of a conurbation region in the U.S. state of Colorado. The conurbation includes one continuous region consisting of the six central counties of Adams, Arapahoe, Broomfield, Denver, Douglas, and Jefferson. The Denver r ...
and serves
Aurora
An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of bri ...
. It also provides direct access to
Denver International Airport
Denver International Airport , locally known as DIA, is an international airport in the Western United States, primarily serving metropolitan Denver, Colorado, as well as the greater Front Range Urban Corridor. At , it is the largest airport in ...
for the
Denver Tech Center Denver Technological Center, better known as The Denver Tech Center or DTC, is a business and economic trading center located in Colorado in the southeastern portion of the Denver Metropolitan Area, within portions of the cities of Denver and Green ...
and the southern suburbs of
Denver
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
. I-225 is one of the two existing auxiliary Interstate Highways in Colorado and it is the only auxiliary route of I-25, as there are no auxiliary routes for I-25 in
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ker ...
and
Wyoming
Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...
. The route begins at I-25 in the Denver Tech Center and runs north to
I-70
Interstate 70 (I-70) is a major east–west Interstate Highway in the United States that runs from I-15 near Cove Fort, Utah, to a park and ride lot just east of I-695 in Baltimore, Maryland, and is the fifth-longest Interstate in the co ...
north of Aurora. It interchanges with
State Highway 83 (SH 83),
SH 30 and
I-70 Business/
US 40/
US 287, known locally as
Colfax Avenue
Colfax Avenue is the main street that runs east–west through the Denver metropolitan area in Colorado. As U.S. Highway 40, it was one of two principal highways serving Denver before the Interstate Highway System was constructed. In the local ...
. The freeway was first proposed in the 1950s along with the first Interstate Highways within Denver. Construction did not begin until 1964 at the I-70 interchange and proceeded south through Aurora until final completion in early 1976 with the final link to I-25 opening to traffic.
Route description
![Int225sEnd-Exit1AB-Int25ns (34095931082)](https://upload.wikimedia.org/wikipedia/commons/b/b4/Int225sEnd-Exit1AB-Int25ns_%2834095931082%29.jpg)
I-225 is one of the three freeways that serves Aurora and is the only existing Interstate in Colorado that never runs concurrent with another highway in its entire length. The southern end of I-225 begins at an interchange with
I-25
Interstate 25 (I-25) is a major Interstate Highway in the western United States. It is primarily a north–south highway, serving as the main route through New Mexico, Colorado, and Wyoming. I-25 stretches from I-10 at Las Cruces, New Mexic ...
, as a typical four-lane Interstate with a limit. The road heads northeastward through southern
Denver
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
,
and, after having exits with DTC Boulevard and Yosemite Street in
Greenwood Village
The City of Greenwood Village is a home rule municipality located in Arapahoe County, Colorado, United States. The city population was 15,691 at the 2020 United States Census. Greenwood Village is a part of the Denver–Aurora–Lakewood, CO Met ...
, the road becomes six lanes with an auxiliary lane in each direction, traversing the Denver–Greenwood Village city limits. With
Cherry Creek State Park
Cherry Creek State Park is a state park in Arapahoe County, Colorado, United States. The park consists of a natural prairie and wetland environment with an reservoir at its center which is shared by powerboats, sailboats, and paddle craft. Th ...
and Cherry Creek Reservoir on its eastside, the highway interchanges with
SH 83 at the northern boundary of the park. Following the exit at SH 83, the freeway enters Aurora,
where it turns northward, maintaining six throughlanes and auxiliary lanes at each exit, a speed limit to its northern terminus at I-70,
and has upgraded exits at Iliff Avenue, Mississippi Avenue, Alameda Avenue, and 6th Avenue (also signed as
SH 30).
After crossing
Sand Creek, the freeway interchanges with
Colfax Avenue
Colfax Avenue is the main street that runs east–west through the Denver metropolitan area in Colorado. As U.S. Highway 40, it was one of two principal highways serving Denver before the Interstate Highway System was constructed. In the local ...
(also signed as
US 40,
US 287, and
I-70 Bus.), and then with 17th Place (serving the Anschutz Medical Campus).
After the exit, I-225 enters
Adams County, continuing through the city of
Aurora
An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of bri ...
. The route then crosses a railroad and continues north, where it interchanges with
I-70
Interstate 70 (I-70) is a major east–west Interstate Highway in the United States that runs from I-15 near Cove Fort, Utah, to a park and ride lot just east of I-695 in Baltimore, Maryland, and is the fifth-longest Interstate in the co ...
.
The northbound ramp to westbound I-70 reenters
Denver
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
, and the eastbound I-70 to southbound I-225 ramp originates in Denver but enters Aurora as it passes under westbound I-70 to southbound I-225 ramp.
Like other state highways in Colorado, I-225 is maintained by the
Colorado Department of Transportation
The Colorado Department of Transportation (CDOT, pronounced See Dot) is the principal department of the Colorado state government that administers state government transportation responsibilities in the state of Colorado. CDOT is responsible f ...
(CDOT), an agency who is responsible for maintaining and constructing transportation infrastructure across Colorado. In 2014, the department's traffic surveys showed that I-225 serves approximately 71,500 vehicles per day between I-25 and Parker Road and 60,750 vehicles north of Parker Road going in and out of Aurora. All of I-225 is part of the
National Highway System (NHS), a network of roads important to the country's economy, defense, and mobility.
History
![Denver, Colorado 1955 Yellow Book](https://upload.wikimedia.org/wikipedia/commons/e/ec/Denver%2C_Colorado_1955_Yellow_Book.jpg)
I-225 was originally proposed by CDOT to be numbered as I-25E on April 3, 1958, based upon the Route Numbering Committee signing north, south, east, and west routes as suffixed routes in the Interstate Highway System. AASHTO rejected the designation, and the highway was then assigned the I-225 designation following further correspondence the following year.
Construction and expansion
Construction on I-225 began in May 1964 at
I-70
Interstate 70 (I-70) is a major east–west Interstate Highway in the United States that runs from I-15 near Cove Fort, Utah, to a park and ride lot just east of I-695 in Baltimore, Maryland, and is the fifth-longest Interstate in the co ...
. A section from
Colfax Avenue
Colfax Avenue is the main street that runs east–west through the Denver metropolitan area in Colorado. As U.S. Highway 40, it was one of two principal highways serving Denver before the Interstate Highway System was constructed. In the local ...
to Sixth Avenue was opened in 1966. The first segment of freeway that ran from sixth Avenue to I-70 received a temporary carrier route that was cosigning I-225 as State Highway 33. CDOT then removed the state highway designation in 1968 as part of an effort to remove carrier routes on existing US and Interstate highways.
Five years later, a segment between Mississippi Avenue and Parker Road was opened, and construction began on another segment south of Parker Road, completed in May 1975. The rest of the route between Yosemite Street and
I-25
Interstate 25 (I-25) is a major Interstate Highway in the western United States. It is primarily a north–south highway, serving as the main route through New Mexico, Colorado, and Wyoming. I-25 stretches from I-10 at Las Cruces, New Mexic ...
was completed in May 1976.
Immediately after the completion of the freeway, improvements at the
SH 30 (6th Avenue) interchange were underway involving the overpass. Reconstruction of the freeway between 30th Avenue and Smith Road took place between October 1992 to August 1994, which involved bridge replacements over Toll Gate Creek and Smith Road that were completed by August 1990 in an effort for the reconstruction project. Two months after the reconstruction project, the I-70/I-225 interchange reconstruction went underway, which involved widening I-225 from I-70 to Smith Road and improvements to the flyover ramps at the interchange that was completed in April 1995. From February 1996 to November 1997, I-225 was expanded to six lanes between Toll Gate Creek and Colfax Avenue and between Colfax and 6th Avenue by December 1997. A new interchange at Alameda Avenue was completed and opened in 2002 and a new flyover ramp at Parker Road began in September 2000 to complete the interchange between Parker Road and I-225. Another interchange at 17th Place was added and opened on February 15, 2013. The portion from I-25 to
SH 83/Parker Road was rebuilt as part of the
T-REX Project
The Transportation Expansion (T-REX) Project was a $1.67 billion project with the goal of transforming the way people in the Denver metro area commute within the areas of Interstate 25 and 225, the country's 14th busiest intersection at the tim ...
completed in 2006.
[T-REX Factbook- Project Background Page 6, https://web.archive.org/web/20041111094231/http://trexproject.com/trex_content/about/trex_2003_factbook.pdf] The highway was later widened between Parker Road and Mississippi Avenue to six lanes, as part of a project to widen the entire freeway to I-70; construction on this portion took place between May 2012 and November 2014. The
RTD R Line, a light rail line, follows the entire length of I-225 from I-25 to near I-70. Its tracks run parallel to the freeway and also use its median and is interlined with a portion of the
RTD H Line. The light rail project was approved in 2004 as part of the
FasTracks
FasTracks is a multibillion-dollar public transportation expansion plan under construction in metropolitan Denver, Colorado, United States. Developed by the Regional Transportation District (RTD), the plan consists of new commuter rail, light r ...
program, began construction in 2012, and was completed in February 2017.
Exit list
See also
*
*
References
External links
Colorado Routes 200-233
{{Good article
25-2
25-2
Transportation in Denver
Transportation in Arapahoe County, Colorado
Transportation in Adams County, Colorado
Transportation in Aurora, Colorado
225
__NOTOC__
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