East Main Street & Idaho-Maryland Roundabout – Grass Valley, CA

In 2007 an initial study was prepared by the city of Grass Valley to improve the intersection of East Main Street and Idaho-Maryland Road. A solution was needed that would improve operations of the intersection and freeway, which were operating at an unacceptable Level of Service (LOS). The project faced numerous challenges, including the need to remain open during construction, limited space, multiple sources of possible contamination, and skewed road alignments.

As part of the environmental review for the partial dual-lane roundabout in the Caltrans right-of-way, H&K performed technical studies associated with the project, including environmental site assessment and geotechnical engineering design. H&K was responsible for providing quality assurance (QA) sampling and materials testing during the construction of the project, which included a southbound-to-westbound bypass lane and dual entry lanes for the Idaho-Maryland approach and large volumes of Miner Concrete (sidewalks, islands, ADA Ramps). H&K provided environmental characterization in addition to QA during the construction phase of the project. Fast-track sampling and response was performed to keep construction on schedule.

The QA testing in the field and laboratory was performed using American Association of State Highway and Transportation Officials (AASHTO), American Society of Testing and Materials (ASTM), and Caltrans Test Methods in accordance with the project’s Quality Assurance Plan (QAP).