Interstate 225

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Interstate 225 connects Interstate 25 near the Denver Technology Center at Hampden South in the city of Denver with Interstate 70 near the interchange with Pena Boulevard. The belt route circles northeast through the city of Aurora from Cherry Creek Reservoir and State Park to Adams County and the Denver city line at the Stapleton and Montbello areas. 2015 traffic counts along the commuter freeway range from 145,000 vehicles per day north of SH 30 (Exit 9) to 149,000 vpd by Cherry Creek Dam.

Interstate 225 Colorado Guides

Interstate 225 was constructed in stages between 1964 and 1976, starting at Interstate 70 and working its way gradually south. The specific milestone dates of the various segments are as follows:1

  • May 1964 - Segment from Interstate 70 interchange south to Colfax Avenue (U.S. 40-287 and Business Loop I-70) is under construction.
  • June 1966 - Segment from Colfax Avenue south to East Sixth Avenue opens.
  • 1969 - Mississippi Avenue Bridges constructed.
  • September 3, 1971 - segment from Mississippi Avenue south to Colorado 83 (Parker Road) opens.
  • May 27, 1975 - segment from Colorado 83 (Parker Road) southwest to Yosemite Street opens>
  • May 21, 1976 - final segment from Yosemite Street southwest to Interstate 25 and U.S. 87 opens.
  • October 1992 to September 1997 - Interstate 225 and Interstate 70 interchange reconstructed in stages.
  • October 1994 - widened to six lanes from Interstate 70 south to Smith Road.
  • November 1997 - widened to six lanes between Colfax Avenue and Sand Creek.
  • December 1997 - widened to six lanes between Sixth Avenue and Colfax Avenue.
  • September 2000 - construction begins on flyover ramp from northbound Colorado 83 (Parker Road) to southbound Interstate 225.
  • 2002 - Alameda Avenue interchange opens (after being approved by voters in November 1997).
  • 2005 - widened to six lanes from Parker Road to Interstate 25 (part of T-REX project).
Denver, CO - 1972

Interstate 225 completed south to Colorado Highway 83 (Parker Road) in 1972.

Additional widening, from July 2010 to summer 2011, added a lane in each direction of Interstate 225 from East Mississippi Avenue (Exit 7) to East 2nd Avenue (just south of Exit 9). The $20.3 million project brought the suburban freeway to six overall lanes from Exit 7 north to I-70. The $43 million upgrade of the Colfax Avenue interchange was underway at the same time.2

Widening of the last four-lane portion, from Exit 7 south to SH 83 (Exit 4), was completed in fall 2014. The overall expansion of I-225 was designed to accommodate a new 10.5 mile stretch of light rail (the R-line) through the corridor.3 The final segment of the 22 mile long R-line opened to the public in the city of Aurora on February 24, 2017.4

Interstate 225 scenes
Iliff Avenue and Interstate 225 meet at a six-ramp parclo interchange in Aurora. Photo taken 02/02/02.
Interstate 225 curves southwest from Iliff Avenue to leave the city of Aurora at the next interchange for south Denver and Cherry Creek State Park. Photo taken 02/02/02.
Iliff Avenue east at the loop ramp for Interstate 225 north. The RTD R-Line now crosses over the arterial in this scene. The shield here was later replaced, and a new assembly was added again here in 2016. Photo taken 02/02/02.
Interstate 225 shields posted at the northbound on-ramp from Colfax Avenue (Business Loop I-70-U.S. 40 west & U.S. 287 north). Photo taken 02/02/02.

  1. Interstate 225 - 50th Anniversary of the Interstate System. Colorado Department of Transportation (CDOT).
  2. "I-225: torn up so it can speed up - Two CDOT projects aim to ease traffic woes." Denver Post, The (CO), July 26, 2010.
  3. "Aurora light rail on track." Denver Post, The (CO), December 1, 2014.
  4. "R-Line ready for its rollout." Denver Post, The (CO), February 18, 2017.

Photo Credits:

02/02/02 by AARoads

Connect with:
Interstate 25
Interstate 70

Page Updated 04-13-2017.

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