Southbound I-25 to westbound US 6 ramp shift coming Dec. 2

Metro Denver Colorado/CDOT Region 1 - Beginning at 10 p.m. on Tuesday, Dec. 2, crews on the Colorado Department of Transportation’s (CDOT) US 6 Bridges Design Build Project will shift the current southbound I-25 off-ramp to westbound US 6 into its new, permanent location. As a result, the ramp will close overnight and reopen by 5 a.m. Wednesday morning.

The existing southbound I-25 to westbound US 6 ramp alignment cuts right through the work zone required to build the new ramp connecting northbound I-25 with westbound US 6 so shifting traffic onto this new, permanent alignment enables completion of the new northbound I-25 off-ramp to westbound US 6.

But while this ramp shift opens up additional work areas, it also creates a challenge in maintaining access to Federal Boulevard for the multiple directions of traffic merging onto westbound US 6. Because this new ramp connects to US 6 at a point that is much closer to Federal Boulevard than the current ramp, there is the potential for merge conflicts between drivers trying to get onto westbound US 6 from southbound I-25 with drivers trying to exit onto Federal Boulevard from either northbound I-25 or westbound US 6.

To eliminate this merge conflict, once traffic is shifted onto this new off-ramp, northbound I-25 and westbound US 6 drivers will no longer be able to access the westbound US 6 off-ramp to Federal Boulevard. Traffic will still be able to access Federal Boulevard if exiting southbound I-25 onto westbound US 6. This configuration will last approximately two months.

“Currently, westbound US 6 traffic has about 1,800 feet to get over and exit at Federal Boulevard,” said Kevin Sullivan, CDOT Project Director. “After this critical ramp shift, that distance would be reduced to about 400 feet. Considering the speed and volume of traffic in this interchange, that would make for an undesirable merge condition. Limiting access to the westbound US 6 off-ramp to Federal Boulevard to traffic coming from southbound I-25 prevents this undesirable weave and will maintain the highest level of safety for the traveling public.”

Crews will also close the Federal Boulevard on-ramp to westbound US 6 between the hours of 10 p.m. and 5 a.m. on Monday, Dec. 1, Tuesday, Dec. 2, and Wednesday, Dec. 3, for drainage line installation.

As always, all construction schedules are tentative and subject to change based on weather or other unforeseen circumstances.


  • During the overnight closure of the southbound I-25 off-ramp to westbound US 6,motorists should go west using alternate routes such as Colfax Avenue, 8th Avenue or Alameda Avenue
  • While access is restricted to Federal Boulevard, motorists should follow these detours:
    • Northbound I-25 motorists should continue north to 8th Avenue, then take 8thAvenue west to access Federal Boulevard.
    • Westbound US 6 motorists coming out of downtown should take Kalamath Street to 8th Avenue or Alameda Avenue, then go west to access Federal Boulevard.
  • During the overnight closures of the Federal Boulevard on-ramp to westbound US 6, motorists should take Alameda Avenue or Colfax Avenue west to Sheridan Boulevard, then take Sheridan Boulevard to the on-ramp to westbound US 6.

PROJECT INFORMATION: The $98 million US 6 Bridges Design-Build Project will replace six obsolete bridges on US 6 between Knox Court and I-25, improve traffic movements in the I-25 and US 6 interchange and enhance driver safety by eliminating several traffic weave movements along US 6 between Federal Boulevard and I-25. Substantial project completion is planned for August 2015.

For updated project information, visit, call 720-881-5540 or email [email protected].


During construction, commuters might want to consider alternative modes of transportation to help ease the impacts of the project. This could include using the Regional Transportation District’s West Rail Line or bus service or taking advantage of carpool/vanpool options. For information on RTD services, call 303-299-6000. For carpool and vanpool information, call 303-458-7665.


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