U.S. 50/Red Hawk Parkway, El Dorado County

The Project

MTCo, as the prime consultant, was sought out and hired by the Shingle Springs Band of Miwok Indians to design a new interchange on U.S. 50 in El Dorado County. The Rancheria had been waiting more than 40 years for a public access road to its reservation, ever since the construction of U.S. 50 in 1965. Previously, the only road available for its use was a winding private road, covered with speed bumps and prohibited from commercial use.

The new interchange features a flyover bridge — a signature four-span, post-tensioned, cast-in-place concrete structure — that carries eastbound off-ramp traffic into the Red Hawk Casino. Eastbound on-ramp traffic passes below two single-span bridges that carry the east and westbound U.S. 50 traffic through the new interchange. Westbound on- and off-ramps complete the interchange, providing for full direct access to the area.

The $45 million interchange required movement of 170,000 cubic yards of earth, approximately 35,000 tons of asphalt concrete for paving the ramps and overlaying U.S. 50, and more than 8,500 cubic yards of structural concrete for the bridges and retaining walls.

The Challenges

Due to severe constraints, MTCo created a custom Type L-11 interchange entirely within Caltrans right of way. In addition to Caltrans involvement, the project included direct coordination with the Federal Highway Administration and the Federal Bureau of Indian Affairs. Once construction began, a tight eighteen month completion date was set to correlate with the grand opening of the new casino.

The Results

MTCo investigated and prepared several preliminary interchange alternatives, prepared a Project Study Report, a separate Project Report, and subsequently prepared full plans, specifications and estimates for the interchange that included all the related structures and other project components.

This interchange was completed on-time and provides a spectacular entrance to the casino and Rancheria. It is seen as a focal point within the El Dorado County region.