Colorado State Highway 470

State Highway 470
Route information
Maintained by CDOT
Length:	27.41 mi[1] (44.11 km)
Major junctions
West end:	US 6 in Golden
	I-70 in Golden US 285 in Morrison US 85 in Littleton
East end:	I-25 / E-470 in Lone Tree
Location
Counties:	Jefferson, Arapahoe, Douglas
Highway system
Colorado State Highways ← US 450 US 491 →

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.

Route description

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.

History

Proposed I-470

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.

E-470

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.

Northwest Parkway

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.[1]

Proposed W-470

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 2010. 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. Some observers estimate that W-470 is more likely to be completed in 2020 than in 2010.

Jefferson Parkway

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.

Exit list

Note: Exits on SH 470 are currently unnumbered.

County	Location	Mile[2]	Destinations	Notes
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
		6.250	Quincy Avenue
		7.901	Bowles Avenue
		10.192	Ken Caryl Avenue
		12.449	Kipling Parkway
		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)
		18.458	Lucent Boulevard
		19.599	Broadway
		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
1.000 mi = 1.609 km; 1.000 km = 0.621 mi      Concurrency terminus •      Closed/Former •      Incomplete access •      Unopened

See also

• E-470
• Northwest Parkway

References

1. ^ "Segment list for SH 470". http://www.dot.state.co.us/app_DTD_DataAccess/Highways/index.cfm?fuseaction=Description&route=470&begRefPt=0&endRefPt=500&Printable=true. Retrieved 2007-05-12. 
2. ^ 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

External links

• Denver's 470 Saga
• Colorado Highways: Routes 400 to 789