CDOT will begin resurfacing CO 46 at Golden Gate Canyon State Park in September

Project Announcement

Aug. 31, 2026 - Denver Metro/Central Colorado - Work includes milling and paving over six miles of highway and making safety improvements

Gilpin & Jefferson County – The Colorado Department of Transportation and contract partner, Martin Marietta, will begin resurfacing Colorado Highway 46 on Tuesday, Sept. 1. The purpose of the project is to improve safety and mobility along this six-and-six-tenths-mile, two-lane highway that runs from Colorado Highway 119 through Golden Gate Canyon State Park to the Jefferson County line. The project will last for about eight weeks, with anticipated completion by Oct. 31.

The scope of work includes milling and paving the highway with two inches of new asphalt to provide a safe, smooth driving surface, adding new lane striping and wayfinding signs, and cleaning culverts for improved storm drainage runoff.

Originally built in the mid-1980s, the highway has undergone routine maintenance and some repaving at the east end over the decades to address age, wear, and freeze-thaw cycles. By resurfacing the full length of the highway, crews will restore the road surface to optimal driving condition, preserve the road base, and ensure the safety of the traveling public.

The project is located from Mile Point 0 at the CO 119 junction in Gilpin County to MP 6.61 at the base of Golden Gate Canyon State Park at the Jefferson County line. Work will be performed during daylight hours (15 minutes after sunrise to 15 minutes before sunset) Monday to Friday, with some overnight work also expected.

Work will begin at the east end of the project limits and progress west, with lane closures and brief holds in place. There will be no scheduled traffic impacts on CO 46 during the extended Labor Day weekend from noon on Friday, Sept. 4 through Monday, Sept. 7, or on Monday, Oct. 5 in observance of Cabrini Day.

Traffic & Bicycle Impacts

  • 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 Fall Foliage Season (Sept. 15-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.
    • 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
  • A 12-foot width restriction will be in place sitewide
  • 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.
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 Information

For additional information about this project:

Know Before You Go

Travelers are urged to “know before you go.” Gather information about weather forecasts and anticipated travel impacts and current road conditions prior to hitting the road. CDOT resources include:

Remember: Slow For The Cone Zone

The following tips are to help you stay safe while traveling through maintenance and construction work zones.

  • Do not speed in work zones. Obey the posted speed limits.
  • Stay Alert! Expect the unexpected.
  • Watch for workers. Drive with caution.
  • Don't change lanes unnecessarily.
  • Avoid using mobile devices such as phones while driving in work zones.
  • Turn on headlights so that workers and other drivers can see you.
  • Be especially alert at night while driving in work zones.
  • Expect delays, especially during peak travel times.
  • Allow ample space between you and the car in front of you.
  • Anticipate lane shifts and merge when directed to do so.
  • Be patient!

Download the COtrip App!

The new free COtrip Planner mobile app was designed to meet the growing trend of information on mobile and tablet devices for the traveling public. The COtrip Planner app provides statewide, real-time traffic information, and works on mobile devices that operate on the iOS and Android platforms. Visit the Google Play Store (Android devices) or the Apple Store (iOS devices) to download!