Interstate 225

Interstate 225 connects I-25 near the Denver Technology Center at Hampden South in the city of Denver with I-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

• North
• South

Starting at I-70 and working gradually south, Interstate 225 was constructed in stages between 1964 and 1976. 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 E Sixth Avenue opens.
• 1969 - Mississippi Avenue Bridges constructed.
• September 3, 1971 - segment from Mississippi Avenue south to SH 83 (Parker Road) opens.
• May 27, 1975 - segment from SH 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 - I-225 and I-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 SH 83 (Parker Road) to southbound I-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).

Additional widening, from July 2010 to Summer 2011, added a lane in each direction of Interstate 225 from E Mississippi Avenue (Exit 7) to E 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 long section 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

scenes

Yosemite Street north at the entrance ramp for I-225 northbound at Hampden South in Denver. The succeeding intersection is with the service road west to Tamarac Parkway and the exchange joining I-225 south with Interstate 25. 04/28/17

Iliff Avenue and Interstate 225 meet at a six-ramp parclo interchange in Aurora. 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. 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. 02/02/02

Mississippi Avenue meets Interstate 225 west of the commercialized intersection with Abilene Street. 07/04/12

Mississippi Avenue passes under a viaduct along the RTD light rail line leading into the exchange with I-225. 07/04/12

Interstate 225 heads north from the diamond interchange with Mississippi Avenue to Alameda Parkway and south to Iliff Avenue. 07/04/12

Business Loop I-70/U.S. 40-287 (Colfax Avenue) west at the northbound entrance ramp for Interstate 225 in Aurora. 04/23/17

Photo Credits:

02/02/02, 07/04/12, 04/23/17, 04/28/17 by AARoads

Connect with:
Interstate 25
Interstate 70
Business Loop I-70 - Golden, Denver, Aurora
U.S. 40
U.S. 287
State Highway 30
State Highway 83

Page Updated 01-17-2022.