Spring 2008
In spring 2008, WSDOT convened a group of acoustics experts to evaluate feasible noise-reducing elements for the I-5 Ship Canal Bridge. These experts identified these potential options for reducing noise in this area:
- For reverberant and/or reflective noise: Noise-absorptive materials on the ceiling above the I-5 express lanes.
- To reduce noise at the source: Replacement or rehabilitation of the pavement.
- To reduce noise near the source: Modify bridge barriers to block/absorb pavement noise.
In addition, the experts made general recommendations for how to approach the unique challenge of noise reduction in the area:
- Model the bridge as an architectural acoustics problem, similar to an amphitheatre, to better understand the reverberant pattern of noise at the project site.
- Focus successive treatments in one geographic location to maximize noise reduction.
- Install a test section along the lanes of traffic.
- Monitor the test section after installation.
Based on the experts' recommendations, we plans to install a test section of noise-absorptive ceiling treatment on the south concrete approach and monitor the results.