Rehabilitation of Structure Nos. N6.49, N6.80E, and N6.80W MP N5.80 to N8.20

Project Description

Due to increased rates of deterioration and traffic impacts as well as rising costs associated with isolated deck repairs/maintenance, several structures (N6.49, N6.80E and N6.80W) along the New Jersey Turnpike's Newark Bay Extension (I-78), west of Interchange 14C in Jersey City, NJ required immediate, full bridge deck reconstruction. As part of this contract, the Interchange 14C Toll Plaza received pavement reconstruction and lighting improvements, the eastbound bridge decks of these three structures were reconstructed, and all three structures have undergone seismic retrofit, structural steel repairs and strengthening, substructure spall repairs, and repainting of structural steel. All construction activities were directly adjacent to noise-sensitive land use, including single and multi-family residential structures, schools, and a recreational facility. Therefore, Paul Carpenter Associates, Inc. (PCA) was retained to perform and document a noise study for this contract as a proactive approach to addressing future perceived noise issues from these noise-sensitive sites during construction.

State and local noise codes were reviewed; however, based on PCA's prior knowledge and experience implementing such codes, PCA was aware that the state code did not address construction noise, while the local code established noise level limits below ambient and work-hour restrictions that would be cost prohibitive and cause scheduling delays, thereby further extending the duration of perceived noise issues by the public. Therefore, to address the needs of the New Jersey Turnpike Authority (NJTA) as well as the affected public, PCA developed project-specific noise criteria. The project-specific criteria included maximum permissible sound level limits as well as work hour restrictions for certain activities to preclude perceived noise issues by the public.

PCA performed a background noise monitoring study, reviewed trends in the data, and developed project-specific noise criteria based on allowing a specific decibel increase over average background noise levels. To ensure feasibility of these criteria and determine time periods that would not comply, PCA performed a detailed construction noise analysis at all noise-sensitive land use. Based on this analysis, a mitigation assessment and design of reasonable measures was performed. The entire noise study process was documented in a technical findings report, including the background noise monitoring study, construction noise analysis, reasonable mitigation measures and work hour restrictions for specific activities.