As part of our integration with Omni-Means, GHD was engaged by
the City of Anderson to study and develop interchange improvement
alternatives, including the addition of a new northbound off-ramp,
at the I-5/Deschutes Road interchange. The need to increase
transport safety and efficiency is driven by large-scale
development proposals in the vicinity.
This study included detailed traffic modeling, traffic
operations analysis, and preliminary design alternatives. We also
prepared a detailed Roundabout Conceptual Approval Report, Project
Study Report, Project Report, and environmental approvals for the
roundabout interchange. After the Traffic Impact Fee Program (also
produced by GHD) was adopted by the City of Anderson and Shasta
County in 2007, funding was secured in 2011 to undertake design
phase 1 of the project, which includes a new off-ramp and
5-leg/2-lane roundabout for northbound traffic.
Overall, the project was particularly complex due to the
addition of the fifth leg to the intersection, a narrow two-lane
Interstate 5 underpass, the relocation of the existing frontage
road, and the Union Pacific Railroad main line overcrossing less
than 500 feet to the east.
Our design alternatives analysis resulted in agreement by all
stakeholders that modern roundabouts at the ramp intersections
provide superior traffic operations at a lower cost than that of a
traditional signalized interchange.