Colorado State Highway 470
|Maintained by CDOT|
|Length:||27.41 mi (44.11 km)|
|West end:||US 6 in Golden|
| I-70 in Golden
US 285 in Morrison
US 85 in Littleton
|East end:||I-25 / US 87 / E-470 in Lone Tree|
|Counties:||Jefferson, Arapahoe, Douglas|
State Highway 470 (C-470, SH 470) is the southwestern portion of the Denver Metro area's beltway. Originally planned as Interstate 470 in the 1960s, the beltway project was attacked on environmental impact grounds and the interstate beltway was never built. The portion of "Interstate 470" that was built as a state highway is the present-day SH 470, which is a freeway for its entire length.
SH 470 begins in Golden, Colorado, starting south from its western terminus at US 6 (6th Avenue) near the intersection with Johnson Road. The highway has interchanges with Interstate 70, State Highway 8, and U.S. Highway 285, then curves to the east. The eastbound portion of SH 470 has interchanges with State Highway 121 (Wadsworth Boulevard), State Highway 75 (Platte Canyon Road), U.S. Highway 85 (South Santa Fe Drive), and State Highway 177 (South University Boulevard). The eastern terminus is the interchange with I-25. Beyond the eastern terminus, the direct continuation of SH 470 becomes the E-470 tollway.
In the 1960s the Colorado Department of Transportation perceived a need for a beltway around the Denver Metro Area and sent a proposal to the Federal Highway Administration. The plan was for the federal government to provide 90% of funds for the project with the state providing the difference. I-470 was added to the Federal Highway Act of 1968 and was to be part of the Interstate Highway and Defense System. The Denver City Council approved the location and began engineering and environmental impact studies. After a few months the studies went under analysis with negative feedback. The Colorado Department of Health was opposed to the interstate beltway on the grounds that it would violate the Federal Clean Air Act. Other studies compared the proposed I-470 to the I-25 and I-225 freeways suggesting that alternate uses for the land (other than freeways) would be more environmentally friendly.
I-470 to Centennial Parkway
The feedback from the Colorado Department of Health caused all efforts to plan and build the beltway to cease by order of the governor. A separate commission was established by Governor Richard Lamm to evaluate the right course of action. The commission came up with 11 alternatives. The final decision was to use federal highway funds to build a grand parkway known as Centennial Parkway (a partial beltway in the southwest portion of the metro area) and widen existing roads.
Centennial Parkway to SH 470
As the southwestern area grew rapidly, plans for Centennial Parkway evolved to conform to freeway standards. The proposed road was designated State Highway 470. Present-day SH 470 is a freeway that is mostly built to interstate standards.
Tollways are planned for the rest of the beltway
After the completion of SH 470 in the southwest, desires for a full beltway persisted in some circles and plans for an extension were created. CDOT did not wish to participate in the building of the freeway extension and left the counties and cities of the metro area to provide funding for the project. The east, north, and northwest portions of the beltway could only be built as tollways.
A tollway extension of SH 470, east and north of the SH 470 eastern terminus, was built to the junction with State Highway 83 (Parker Road) and termed Eastern/Extension 470 or E-470. Subsequently, E-470 was extended to the interchange with I-70 in the east, and later to I-25 in the north. This newly added tollway was built and continues to be administered by a quasi-governmental organization known as the E-470 Public Highway Authority.
When highway interests pushed for the rest of the beltway to be completed, the city of Golden voted to stop all efforts to finish the beltway due to traffic concerns. The city and county of Broomfield, Colorado effected an 11-mile (18 km) continuation of the E-470 tollway from I-25 to an interchange with US 36 (the former Denver-Boulder Turnpike) near Flatiron Crossing Mall. This section of the tollway is known as the Northwest Parkway, and is administered, similarly to E-470, by its own quasi-governmental agency. In combination with E-470 (47 miles) and SH 470 (27 miles), the Northwest Parkway brings the total length of the completed portion of the beltway around the Denver-Aurora Metropolitan Area to approximately 85 miles (137 km). The uncompleted portion, from the west end of the Northwest Parkway to the northwest end of SH 470, is 19 miles (31 km) along existing streets.
In 2007, the Portuguese company BRISA paid $603 million to operate the road for the following 99 years  The lease included a clause restricting a "Competing Transportation Facility. This clause was invoked in an April 30, 2008 letter when Broomfield wished to make changes to 160th Ave.
As of August 2003, CDOT made a compromise with the cities of Westminster, Arvada and Golden to do an environmental impact study, the first step in an attempt to complete the beltway by 2020. The last segment of the beltway would be another tollway, tentatively called W-470, and would connect the west end of the Northwest Parkway to the northwest end of SH 470.
The Jefferson Parkway is the planned extension to the beltway to begin at the Northwest Parkway and end at SH 93. It is currently in its planning phase. Jefferson County, Broomfield and Arvada have formed the Jefferson Parkway Public Highway Authority to construct the highway.
Note: Exits on SH 470 are currently unnumbered.
|Jefferson||Golden||US 6 (6th Avenue)||Westbound exit and eastbound entrance; west end of SH 470|
|0.001||I-70 west – Grand Junction|
|0.001||I-70 east – Denver||Westbound exit and eastbound entrance|
|1.842||SH 26 (Alameda Parkway)|
|Morrison||4.248||SH 8 (Morrison Road)|
|Lakewood||5.699||US 285 (Hampden Avenue) – Fairplay, Denver|
|10.192||Ken Caryl Avenue|
|13.902||SH 121 (Wadsworth Boulevard)|
|15.443||SH 75 north (Platte Canyon Road)||Westbound exit and entrance|
|Douglas||Littleton||17.000||US 85 (Santa Fe Drive)|
|21.069||SH 177 (University Boulevard)|
|Lone Tree||24.144||Quebec Street|
|25.574||Yosemite Street||Eastbound exit and westbound entrance|
|26.195||I-25 – Colorado Springs, Denver||East end of SH 470; continues east as E-470|
The completion of the road has been mired in controversy. In 1975 Colorado Governor Dick Lamm vowed to "drive a silver spike" through the plans for the road. In 1989 voters turned down an expansion of the road by a four-to-one margin. In the late 1990s a citizens group called Citizens Involved in the Northwest Quadrant (CINQ) was formed to oppose the completion of the road. In 2008, a group of Arvada residents sued to try and stop the city from joining the newly formed JPPHA.
The completion of the road continues to have a primary proponent in the city of Arvada and the city of Broomfield who feel, among other things, it will financially benefit them. A number of localities, including the Town of Superior, the city of Wheat Ridge, and the city of Golden have fought the completion of the road citing, among other things, a decrease in their quality of life.
- "Segment list for SH 470". Retrieved 2007-05-12.
- "Plans to Complete Beltway". Broomfield Enterprise. July 24, 2008.
- Lewis, Al (September 2, 2007). "Parkway Lease Fool's Gambit". Denver Post.
- Colorado Department of Transportation, Highway Data, accessed December 2007: note that not every interval between mileposts is exactly a mile, explaining why more exits than expected are at the exact milepost
- Steers, Stuart (June 19, 1997). "The Blacktop Jungle". Westword.
- Flynn, Kevin (2008-06-14). "Arvada clears beltway hurdle". Rocky Mountain News.