Interstate 270 Colorado


Interstate 270 is a short connector freeway linking Interstate 70 with Interstate 25 and U.S. 36 in northeast Denver and Commerce City.


Interstate 270 was originally to be designated as Interstate 425, but Interstate 270 was chosen instead.1 Construction of the freeway began on December 12, 1965, and the freeway between Interstate 70 and Interstate 76 (80S) was completed by October 23, 1970. On April 7, 2000, the Route Numbering subcommittee of AASHTO approved the extension of Interstate 270 from Interstate 76 northwest to Interstate 25 (contingent upon approval by the Federal Highway Administration). This section of freeway opened in both directions by 2002.

For more details on the history of the completion of Interstate 270 in Colorado, visit Interstate 270 @ AARoads.

Planned Improvements

Through the 1990s and 2000s, Interstate 270 has been improved through the Interstate 76 and Interstate 25 interchanges to improve access. The highway previously ended at Interstate 76, but the westbound direction was extended to Interstate 25 and U.S. 36 in 2001 and the eastbound direction was connected to U.S. 36 and Interstate 25 in 2002. Shown on some maps as Colorado 270 in 2002 and signed variously as "Future Interstate 270" and "Interstate 270," the freeway is now part of Interstate 270. Interchange improvements to this route continue, and completion of all aspects of the route (excepting a full access ramp at Interstate 76) occurred in 2005.

Highway Guides

Western Terminus - Interstate 25 - near Commerce City, Colorado
Perspective from Interstate 270 west
Originally, the west end of Interstate 270 was at Interstate 76. To get to Interstate 25 or U.S. 36, one had to go west a bit on Interstate 76. But in 2000, westbound Interstate 270 was extended, such that it now has a direct connection to northbound Interstate 25 and westbound U.S. 36 (the Boulder Turnpike). Photo taken by Dale Sanderson (04/01).
Further ahead, CDOT posted an End sign, which is not consistently done in the state. Even though the sign displays Interstate 270, it should display Future Interstate 270. The sign behind that is a Begin sign for U.S. 36, which had been quietly overlapped with Interstate 270 for its entire length. This is not the beginning of U.S. 36 westbound; this is a continuation. U.S. 36 merges with Interstate 70 near Strasburg, then silently takes Interstate 270 northwest toward the Boulder Turnpike. CDOT does not normally use BEGIN signage, so this sign is out of character for Colorado highways. Denver metropolitan area signs indicate how to follow U.S. routes through the city, so it is wise to bring a good map when traveling through the area. Photo taken by Dale Sanderson (04/01).
Perspective from Interstate 76 east
As of February 2002, eastbound Interstate 270 still begins at Interstate 76, and minimal work has been completed to build the eastbound lanes. It is unclear as to when its direct connection with U.S. 36 will be done, but the entire project is expected to be complete in 2005. Photo taken by Dale Sanderson (04/01).
Perspective from Interstate 76 west
One half mile east of the Exit 6B/A interchange with Interstate 270 on Interstate 76 west. Interstate 270 panels include a U.S. 36 trailblazer for the Denver-Boulder Turnpike to the northwest and Interstate 70 for the return southeast. Photo taken 02/02.
Centerline upcoming exits post revealing the Exit 6B/6A and 5A interchanges with Interstate 270 and nearby Interstate 25. The 45 MPH speed limit is in relation to construction present at the time of this photograph. Photo taken 02/02.
Eastern Terminus - Interstate 70 - Denver, Colorado
Perspective from Interstate 270 east
The eastern terminus of Interstate 270 as the freeway merges onto Interstate 70. The semi-truck is on mainline of eastbound Interstate 70. The collector-distributor lanes carrying Interstate 270 traffic onto Interstate 70 merges onto the freeway just ahead of this photo. Photo taken by Dale Sanderson (04/01).
Perspective from Interstate 70 west
0.75 mile overhead for Exit 279/Interstate 270 west on Interstate 70 west. In addition to the control city of Fort Collins due to the connection with Interstate 25 north, the northwest suburb of Westminster is featured. This community is to the northwest of the terminus along the U.S. 36 Denver-Boulder Turnpike. Photo taken 02/02.
Interstate 70 west at the Interstate 270 westbound beginning. An interesting road, Colorado 35 leads from Interstate 270 to the front door of the old Stapleton International Airport. With the construction of Denver International, it is surprising that Quebec Street/Colorado 35 has not been decommissioned and maintenance given to the city of Denver. Colorado 35 is a semi-freeway, with a stoplight at the exit at Interstate 70 and a complete interchange with Smith Road just south of Interstate 70. South of there, the road composes a multiple lane divided highway with stoplights. Photo taken by Dale Sanderson (04/01).
The Interstate 70/270 split as seen just after daybreak on Interstate 70 westbound. Colorado 35 composes the next westbound interchange and also composes the last Interstate 270 eastbound off-ramp as well. Photo taken 02/02.


  1. Post by Stephen Summers on misc.transport.road newsgroup: "Interstate Numbering AASHTO and FHWA," April 18, 2003. Mr. Summers also posted a map showing Interstate 425 from planning documents on his webpage, but the webpage is no longer on the Internet.

Page Updated March 25, 2006.

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