C-470 & Quincy Roundabouts

Dec. 21, 2024 to Feb 18, 2025 - the project will be in winter shutdown, with no traffic impacts.

About the Project

Interchange improvement project at State Highway 470 and West Quincy Avenue in Jefferson County. Work includes adding a single lane roundabout with bypass lanes at the Quincy and C-470 northbound ramp intersection, and a T-intersection with traffic signal at the Quincy and C-470 southbound ramp intersection. Other work includes road widening, building retaining walls, adding signs, and making drainage improvements.

Project Benefits

  • Improve traffic flow to and from C-470 from Quincy Avenue
  • Construct a roundabout at the northbound ramp intersection, a proven method of safely managing traffic at certain intersection
  • Upgrade ramps to support increased traffic
  • Add a traffic signal to the southbound ramp intersection for improved safety

Work Schedule

  • Work began on May 13 with an anticipated duration of 18 months

  • Project hours are 7 a.m. to 6 p.m. Monday to Friday

  • Overnight and weekend work is also expected

Traffic Impacts

Motorists can expect the following impacts during the period of construction:

  • Periodic on and off ramp closures to and from C-470 at Quincy Avenue during off-peak daytime as well as overnight hours
  • Some closures of half the existing Quincy Avenue over C-470 bridge will be taken for roundabout and other construction, with two-way traffic maintained and 12-foot width restriction in place
  • A single lane closure on northbound C-470 will exist later in the project for sign work
  • Onsite detour pavement will be built to route traffic around the proposed roundabout location
  • Other detour routes will be marked for use during later phases of construction
  • Signs and construction devices will be present to alert the public to the work zone, closures and restrictions
  • All construction schedules are weather dependent and subject to change
  • Refer to COtrip.org for real-time travel conditions and road closures

Work this Week & Lane Closures C-470 & Quincy Roundabouts

Project Facts

  • Construction Cost: $6.2 Million
  • Contractor: Villalobos Concrete, Inc.
  • Timeline: May 2024 through late 2025 (Winter shutdown Dec. 21, 2024 to Feb. 18, 2025)
  • Location: C-470 and West Quincy Avenue 
    • Nearest Town/City: Morrison
    • Mile Point(s): MP 6.10 to 6.80
    • County: Jefferson
C-470 Quincy Roundabouts project location map
C-470 and Quincy Roundabouts project location