US 36 Design-Build

Completion of the design-build reconstruction of US 36 between Boulder and Denver in Colorado offers unique multi-modal options for commuters that will provide greater capacity and help relieve traffic congestion.

The two-phased alternative delivery project added express lanes for Bus Rapid Transit (BRT), High Occupancy Vehicles (HOV), and tolled Single Occupancy Vehicles (SOV). It will also have a bikeway alongside the highway that ties into the existing trail systems. Phase 1 of the project began in April of 2012, and tolling has been fully operational since July of 2015. Phase 2, a Public-Private Partnership (P3) was started in October of 2013 and was completed in the spring of 2016. The project included construction of four new bridge structures, widening two existing bridge structures and repair to 15 bridges along the HOV lane.

One of the expansion project’s unique features is the use of a Diverging Diamond Interchange (DDI). Traffic crosses to the opposite side of the road so vehicles have unimpeded movement onto the freeway. Despite using fewer lanes, this innovative interchange can handle more traffic, reduce traffic signal delays, increase left-turn capacity and eliminate wrong-way entry to ramps. This is just the third DDI to be built in the State of Colorado.

The 16 miles of combined Phase 1 and 2 construction required installation of 1.3 million square yards of concrete paving. RSA maintained a crushing yard on site to reduce hauling and mobilization of materials, and all of the project’s asphalt paving has been recycled and reused throughout the project.