Pre-qualification: State Route 85 Noise Reduction (Phase 2) Project

The SR 85 freeway was constructed in two different eras: the northern portion of the corridor was constructed
in the 1960s (north of I-280) and the southern portion of the corridor was constructed in the early 1990s
(south of I-280). Per the Santa Clara County Ordinance, Sec. B17-5.4, trucks were banned on SR 85 south of I-
280 when the newer southern portion of the corridor was opened to traffic to eliminate the additional noise
that truck traffic would generate. However, as traffic volumes have continued to increase on SR 85, noise
levels have increased too, and adjacent communities have requested better noise abatement. Caltrans has
developed new acoustic measurement techniques and studied options to better reduce noise levels.

In 2006, VTA completed a high precision diamond grinding and grooving project on SR 85 between SR 87 and
I-280 (after the public responded favorably to a 0.88-mile test section), to conduct tire/pavement interface
noise evaluations that compared existing longitudinal tined surfaces to the new diamond ground and grooved
textured surfaces. The goal of the project was to remove the roadway’s existing longitudinal tining that was
generating noise levels that were greater than desired.

To address current traffic noise concerns along SR 85, VTA is working with Caltrans and cities along the SR 85
corridor to study, analyze, and implement noise reduction treatments through a three-phase Noise Reduction
Program. Phase 1 was the initial study phase that recommendeded the specific treatments to reduce the
amount of noise generated and identified five demonstation locations to construct the additional noise
reduction measures. This Phase 2 Project, the demonstration phase, consist of constructing the noise
reduction measures at the five demonstration locations and completing a before and after noise level study
to determine how much of a reduction was achieved and the cost to achieve that level of noise reduction. A
potential future Phase 3 project would be the construction of these same noise reduction measures on
significantly longer segements of SR 85 and possibly even corridor wide. These three phases make up the
entire State Route 85 Noise Reduction Program.