Interstate 270

Length: 5.35 (I-25/US 36 to I-70)
Exits: 6
Counties: 2 (Adams and Denver )
Cities: 2 (Commerce City and Denver)
Start of Construction: 1965
End of Construction: 1970
Initial Construction Costs: $8.9 million

National Impact

Use to benefit travel to and from Stapleton International Airport .

Construction Timeline

I-270 started being built in the late 1960s. The section from I-70 to Vasquez opened by 1968, and it opened up to I-76 by 1970. As originally built, I-270 started at a trumpet interchange on I-76 just east of I-25. Two lanes from eastbound I-76 blended off and become I-270, while from I-270 the two lanes merged onto westbound I-76, but those immediately became the exit lanes for northbound I-25 and westbound US 36.

Westbound US 36 connection history: In September 1999, the connection from WB I-270 to NB I-25 opened. If you wanted US 36, you still had to take the former route that mainline I-270 took west onto I-76. Then in mid-February 2000, the full westbound connection finally opened. Also opening was an exit from WB I-270 to Broadway. At the same time, several other things happened: A new exit from I-76 westbound to I-270 westbound opened, and the preexisting exit from westbound I-76 to NB I-25 and WB US 36 closed. Also the ramp from WB US 36 to Broadway closed, replaced by a new exit from NB I-25 to 70th Avenue .

As for the eastbound connection, the full connection from US 36 to EB I-270 opened August 16, 2003. No other ramp openings or closings happened with that, though.

December 12, 1965 Construction of I-270 begins. Major structures include twin bridges to take I-270 over Dahlia Street , a bridge to carry Quebec Street over I-270 and another two to take I-270 over I-70. Cost: $1.4 million for structures and $1.3 million for paving; Contractor: L.H. Kilgroe Construction Co. of Denver .

August 2, 1968 A three-mile segment of I-270 between Vasquez Boulevard and I-70 opens to traffic.

October 23, 1970 A two-mile segment of I-270 opens to traffic between I-80 (I-76) and US 85, adjoining the three-mile segment already in service. This segment completes the 5.2 mile circumferential route.

April 1993 Construction begins to extend I-270 from I-76 to the I-25/US 36 interchange. Phase I consists of extends I-76 from I-25 to Pecos Street, constructing an eastbound I-270 bridge over I-25 and reconstructing the east to northbound and east to southbound ramps. Cost: $11.4 million; Contractor: Centric/Jones Constructors; Complete: June 1994

June 1996 Cost: $12 million Contractor: Centric-Jones Co. Work: Constructed a total of five new bridges. Two of the bridges were for westbound I-270 over Washington Street and over I-25. Two bridges were for the exit ramp from northbound I-25 to 70 th Avenue . The final bridge connected northbound I-25 to westbound US 36. Duration: June 1996 through May 1998

July 1997 Cost: $9 million Contractor: SEMA Construction Co., Inc. Work: Constructed the I-270 westbound bridge over Clear Creek, widened the existing US 36 bridge over Broadway, realigned southbound I-25 to the westbound US 36 ramp, which included the construction of MSE walls. Duration: July 1997 through December 1998

June 1998 Cost: $19 million Contractor: Centric-Jones Co. Work: Completed the westbound I-270 extension between I-76 and US 36, built the Direct Connect HOV ramp between US 36 and I-25 and constructed a new alignment of northbound I-25 between I-76 and 84 th Avenue . Duration: June 1998 through June 2001

March 1999 Construction begins to replaces the I-270 bridges over Vasquez Blvd. Cost: $6.2 million; Contractor: PCL Civil Constructors; Completion: June 2000

October 1999 Cost: $8.5 million Contractor: Hamon Contractors, Inc. Work: Constructed eastbound I-270 from I-25 to York Street , including the new bridge structures at I-270 over Washington Street and I-270 over Clear Creek. This project was accelerated one year due to TRANs bonds. Duration: October 1999 through March 2002

June 2000 Cost: $21 million Contractor: Hamon Contractors, Inc. Work: Constructed seven structures at the I-270 and I-76 interchange, rebuilt ramp movements from westbound I-270 to eastbound and westbound I-76. This project was accelerated two years due to TRANs bonds. Duration: June 2000 through August 2003

March 2004 Cost: $21 million Contractor: SEMA Construction Co., Inc. Work: Constructed a flyover ramp from southbound I-25 to eastbound I-270 and reconstructed southbound I-25 in concrete between 84 th Avenue and I-76. This project would not have been constructed without TRANs bond monies. Duration: March 2004 through November 2005

Future Cost: $15 million Contractor: Yet to be determined Work: Constructs a flyover ramp from eastbound I-270 to eastbound I-76. Duration: On hold (depend on funding) - This is the final phase of this Strategic Transportation Project.

CDOT Personnel

C.W. “Chet” Andersen F.P. McNamara
Skip Hlad Jake Koenig
Moe Awaznezhad John Schwab
Daryl Miller Jim Powers