US 101 Managed Lanes, Santa Clara to San Mateo Counties, CA
I&R prepared the noise study for the US 101 Managed Lanes Project, which proposed to add an HOV lane in each direction on US Highway 101 from the terminus of the Santa Clara County express lanes to I-380 in northern San Mateo County, California, over a total alignment length of 22 miles. As part of the project, many existing noise barriers were proposed to be relocated. The project alignment experienced heavy congestion during most waking hours, resulting in an innovative noise measurement survey approach. The noise study included identification of potential sensitive receptors, measuring existing noise levels at 120 locations, developing and validating the TNM noise model, modeling existing and future noise levels, identifying noise impacts, evaluating noise the feasibility and reasonableness of noise abatement, prediction of construction noise levels, and documentation of results in a noise study report.