Santa Fe and Mineral Improvements

Progress is being made on the Santa Fe and Mineral Improvements Project as construction continues on the Denver metro area’s first quadrant road interchange.

A concrete box culvert on the south side of Mineral Avenue at Platte River Parkway has been installed, and grading, soil preparation, and storm sewer installation for the quadrant road are ongoing. A major traffic shift on to accommodate ongoing construction will be implemented in late February.

This update includes notice of an upcoming travel advisory as well as construction progress and planned work for the Santa Fe and Mineral Improvements project in Arapahoe County.

Upcoming Travel Advisory: Starting within the next month, both directions of traffic on Santa Fe Drive (US Highway 85) within the project limits will be shifted east into a temporary alignment to accommodate widening and other work on the west side of the work zone. The shift will take place over a two-night period, with lane closures in place and delays expected. Once implemented, two through lanes and a dedicated single left turn lane will remain in place in both directions of Santa Fe Drive until further notice. A notification will be sent once dates are confirmed.

Since the last update, crews have finished backfilling and waterproofing the concrete box culvert and have begun installing concrete pipe and inlets for the new drainage system. Ongoing work includes excavating for the new quad roadway, and removing asphalt and concrete on Mineral Avenue west of the Santa Fe Drive intersection.

Planned work over the next two weeks includes excavating and placing road base for the new quad roadway, installing drainage pipe and inlets, and building embankment areas. Other work includes preparing for the traffic shift, removing asphalt and concrete, and replacing the traffic signals at Mineral and Platte River Parkway with three-way stop signs. These signs will remain in place until further notice.

Image caption: Recent views of the concrete box culvert and excavation for the new quad roadway.

Travel Advisory & Project Update

Starting on Thursday, Jan. 22, 2026 and lasting until about 5 p.m. on Friday, Jan. 30, the City of Littleton and the Colorado Department of Transportation will close the far left turn lane from northbound Santa Fe Drive (US HIghway 85) to westbound Mineral Avenue and close the left lanes in both directions of Mineral Avenue within the project limits. These traffic impacts will remain in place during the nine-day period as part of the Santa Fe and Mineral Improvements project.

The closures are necessary so crews can remove portions of the existing median and begin widening and traffic signal improvements on the west side of the project corridor at the Platte River Parkway and Mineral intersection.

Other work underway sitewide includes backfilling and waterproofing the newly installed concrete box culvert in the southwest portion of the project, installing storm drainage pipe and inlets, potholing, and starting excavation for the new quad roadway.

Traffic Impacts

Thursday, Jan. 22 to Friday, Jan. 30 - Left turn lane closure from north-bound Santa Fe Drive to westbound Mineral Avenue & left lane closures in both directions of Mineral Avenue.

• The far left turn lane on northbound Santa Fe Drive to westbound Mineral Avenue will be closed from approximately 7 a.m. on Thursday, Jan. 22 to 5 p.m. on Friday, Jan. 30. The second left turn lane will remain open.
• Left lane closures will also be in place in both directions of Mineral Avenue within the project limits during this nine-day period, reducing traffic to a two-way, single lane alignment.
• The closures will remain in place 24 hours a day.
• Please refer to the map for lane closure information.
• The project limits on Santa Fe Drive extend from Mile Point 201 to MP 202, approximately half a mile south to half a mile north of the Mineral Avenue intersection.
• The project limits on Mineral Avenue extend from west of Platte River Parkway to east of the Santa Fe Drive intersection.
• Signs and construction devices will be present to alert the public to the closures and work zone restrictions and to maintain safety.
• Delays can be expected and caution is advised.
• Visit LittletonCO.gov/ConeZone for traffic impacts.

Work includes removing asphalt and concrete, and performing traffic signal and utility work at the Platte River Parkway and Mineral Avenue intersection.

Image caption: Location of the lane closures that will be in place from Jan. 22 to Jan. 30 for the City of LIttleton's Santa Fe and Mineral Improvements project.

Littleton leaders and regional partners broke ground on the Santa Fe and Mineral Improvements Project November 19, kicking off the project to build an innovative “quad road” at the congested intersection.

Following years of public outreach, planning, and design, the intersection of South Santa Fe Drive and West Mineral Avenue will see major improvements aimed at reducing traffic delays and improving safety.

With as many as 60,000 vehicles per day on Santa Fe and 30,000 on Mineral, drivers can currently experience delays of up to 20 minutes during peak times. If the intersection were to remain in the current configuration, delays would become significantly worse given traffic volumes are projected to grow to 115,000 vehicles per day through the intersection by 2040 due to anticipated future development in the region.

To address these issues, the city is constructing a new “quadrant roadway” in the southwest corner of the intersection. This innovative design will remove left turn movements from the intersection and reroute left-turning traffic onto a separate roadway, freeing up green-light time for through movements and improving overall flow.

Construction will begin this fall on the Santa Fe and Mineral Improvements Project, a long-planned upgrade to the most congested intersection in Littleton.

The intersection of Santa Fe Drive and Mineral Avenue will soon see major improvements aimed at reducing traffic delays and improving safety. With as many as 60,000 vehicles per day on Santa Fe and 30,000 on Mineral, drivers can currently experience delays of up to 20 minutes during peak times.

To address these issues, the city is constructing a new quadrant roadway in the southwest corner of the intersection. This innovative design will reroute left-turning traffic onto a separate roadway, freeing up green-light time for through movements and improving overall flow.

The project includes new traffic signals, lane configurations, and timing adjustments, along with other mobility and safety upgrades in the surrounding area.

Construction is expected to begin this fall and will take approximately two years, with completion anticipated in fall 2027. Work is scheduled to start on land southwest of the intersection. Traffic impacts will be posted to the Cone Zone page at LittletonCO.gov/ConeZone.

The City of Littleton is hosting a self-guided online meeting for residents to learn more about transportation improvements in the Santa Fe Drive and Mineral Avenue area, including Littleton's Santa Fe and Mineral Improvements Project, Mineral Mobility Improvements (East and West), and Douglas County's US-85 Improvements Project.

This area of Littleton is undergoing transportation improvements to enhance safety for motorists, pedestrians, and bicyclists, to reduce traffic congestion, and to provide more convenient and comfortable connections. These planned changes will also enhance many local and regional destinations, including RTD's Mineral Light Rail Station and local businesses.

Visit the self-guided online meeting to learn more, submit comments or questions, and sign up for each project distribution list to be notified of project updates. The online meeting will be available through Friday, July 28.