CO 46 Resurfacing in Gilpin & Jefferson Counties

About the Project

The project consists of milling and paving 6.6 miles of Colorado Highway 46 to provide a safe, smooth driving surface, adding new lane striping and wayfinding signs, and cleaning culverts for improved storm drainage runoff.

Project Facts

  • Construction Cost: $2.6 million
  • Contractor: Martin Marietta
  • Timeline: September 2026 to October 2026
  • Location: CO 46
    • Nearest Town/City: Black Hawk
    • Mile Point(s): MP 0 to MP 6.6
    • Counties: Gilpin and Jefferson
Map of location and limits of construction of the Colorado Highway 46 Resurfacing project in Gilpin and Jefferson County.
Map of location and limits of construction of the Colorado Highway 46 Resurfacing project in Gilpin and Jefferson County.

Project Benefits

Goal is to improve safety and mobility along a two-lane highway in Gilpin County. Benefits include:

  • Restoring the road surface to optimal condition
  • Restriping and adding signs to improve safety and visibility

Work Schedule

  • Project begins Sept. 1, 2026 with anticipated completion by Oct. 31.
  • Work will be performed during daylight hours (15 minutes after sunrise to 15 minutes before sunset) Monday to Friday
  • Expect some overnight work

Traffic Impacts

The following impacts can be expected during construction:

  • Motorists can expect single daytime lane closures for up to one mile in length, with traffic holds up to 10 minutes, Monday to Friday
  • Temporary access disruptions to private driveways, business entrances and approaches to and from side streets will exist in the first few weeks of the project
  • Addresses can expect up to two days of impacts and 10-minute delays, managed by flagger operations
  • During the Fall foliage season (Sept. 15 to Oct. 31), lane closure lengths will be reduced to half a mile
  • Only one lane closure will exist at a time within the work zone
  • Shoulder closures can be expected outside lane closure areas within the project limits
  • Work will progress from east to west
  • A 10-foot width restriction will be in place
  • During lane closures, bicyclists traveling westbound (uphill) will be queued and permitted to clear the work zone before vehicles, followed by a pilot car
  • Downhill bicycle traffic (eastbound) will be held by flaggers and only permitted to proceed through the work zone after the last vehicle has been released from the queue
  • Access to the Blue Grouse Trail and Beaver Trail will be maintained at all times
  • Reduced speeds can be expected
  • Signs and construction devices will be present to alert motorists and bicyclists to lane closures, traffic shifts and other work zone restrictions
  • Refer to COtrip.org for real-time travel conditions and road closures