Interstate 280 Soundwalls Project Engineering Services

This project to construct soundwalls at five locations includes a soundwall on and in the vicinity of the Los Gatos Creek Bridge, Bridge No. 37-265. The aesthetics of the soundwall had been previously established and will complement the appearance of the other soundwalls built in the area. The proposed soundwall will be supported on a new MASH-compliant and crash-tested barrier on the existing bridge deck overhang.

Noise levels in the vicinity of the project exceed limits based on Section 215.5 of the Streets and Highways Code (Freeway Noise Attenuation). Construction of soundwalls along both sides of Interstate 280, within the project limits, is recommended as an effective noise abatement measure.

The current scope of work is for the Project Approval/Environmental Document (PA/ED) services for this project. MNS reviewed the soundwall layouts shown on the NBSSR for further study and to fine-tune the scope of the project. The MNS Design Lead expanded on the previous soundwall layouts and defined the improvements in sufficient detail to obtain the appropriate agencies consensus on preliminary soundwall layouts that will be discussed in the PR prepared and recommended for the subsequent final design PS&E phase. The Interstate 280 Corridor within project limits is an eight-lane freeway, with one auxiliary lane in each direction, that goes through residential areas and has experienced increased levels of ambient noise. The current project has been prioritized on the State HB311 candidate project list.