CDOT I-70 Floyd Hill Technology, Design & Engineering

Colorado’s Interstate 70 (I-70) Mountain Corridor is a notoriously congested, treacherous stretch of highway that leads to some of the state’s most popular recreational destinations. It also serves as a main east-west throughway for long-haul trucks and the primary truck route for goods to Summit County and towns on the West Slope.

To enhance safety and mobility along the route, the Colorado Department of Transportation (CDOT) is upgrading eight miles of the corridor west of Evergreen to eastern Idaho Springs. Once finished, the project will address the bottleneck on I-70 at Floyd Hill and improve traffic flow, access at major interchanges and frontage-road intersections and stopping sight distance on horizontal curves.

As the engineer of record and lead designer for the project, we are leveraging digital technology to help CDOT make these improvements, which include:

• Constructing a westbound, tolled Express Lane just west of Homestead Road through the Veterans Memorial Tunnels to Colorado Blvd./Idaho Springs
• Constructing a missing two-mile section of the frontage road between US 6 and the Hidden Valley/Central City Parkway interchanges, which will improve emergency response
• Constructing an extended on-ramp from US 6 to eastbound I-70, giving slow-moving vehicles more room to merge
• Replacing six bridges in accordance with today’s safety standards
• Providing two wildlife passageways underneath bridge spans connecting previously separated natural areas affecting migration and roaming
• Installing two permanent, air quality monitors

To facilitate collaboration among a large, multi-regional, diverse, internal design group, as well as external consultants and stakeholders, our team is using Computer-Aided Design (CAD) tools for roadway design, signage design and placement, drainage network analysis and modeling. Utilizing these digital tools enabled the creation of a roadway model as the design progressed and allowed other disciplines to reference that model to federate additional design components such as the drainage pipe network, underground utility placement and structure foundations. All structures, including bridges, abutments and walls, were analyzed, designed and modeled, with parametric cells developed for pier design and modeling. Integrated Design Review tools allowed everyone involved on the project to mirror our five-step, quality control process, including customized forms, formal notification to reviewers and task leads and tracking of the closure of comments from previous milestone submittals.

CAD technology also helped us mitigate impacts to the surrounding environment while enhancing wildlife connectivity, air and water quality, stream conditions and recreation. By importing environmental GIS layers with automated geographic reprojection, the team could geo-locate shape files featuring sensitive areas such as critical or endangered species, wetland and riparian areas. Using these files, our engineering team identified these locations in their plans and modified the proposed designs to avoid negative impacts. In addition, by assessing Americans with Disabilities Act (ADA) and multimodal requirements while minimizing impacts to natural areas, digital tools made it possible to optimize ADA improvements to the Clear Creek Greenway Trail, which include constructing approximately 1,500 feet of new trail in areas previously inaccessible in Clear Creek Canyon. We also used this technology to determine the environmental impact of bridge piers and abutments by developing 3D models that enabled the visualization of these improvements during viewshed analysis.

Construction is currently underway, with the project expected to be completed in 2028. To date, digital tool utilization has helped reduce hours worked by more than 50,000 and project costs by more than $7 million.