Deck reconstruction and miscellaneous improvements were slated for fifteen high priority bridges along the Garden State Parkway (GSP) between Old Bridge Township (near Interchange 120) and Paramus (just north of Interchange 160), New Jersey. An assessment of the potential noise impact of each bridge reconstruction project was performed based on site sensitivity and construction schedule to determine whether a project specific noise level limit placed within the contract specifications would be beneficial to minimize community impacts.
A background noise monitoring study was performed for each bridge at representative noise sensitive locations. Long-term noise monitoring was performed for at least two weeks in each location to establish background noise levels on weekdays and weekends. Data sets were filtered based on abnormal traffic patterns, adverse meteorological conditions beyond equipment tolerances, and extraneous noise sources. Trend graphs were developed based on the long-term data in order to develop average background noise levels covering noise-sensitive time periods coinciding with proposed work hours. Project-specific noise level limits were developed based on allowing the contractor a specific level over the average background noise level for each time period in order to allow the contractor to perform work with reasonable mitigation measures while protecting noise-sensitive land use.
In addition, construction noise analyses were performed utilizing representative case scenarios at the closest noise sensitive receptors. Results of these analyses were used to identify activities that would require reasonable mitigation measures in order to meet proposed construction noise level limits and work restrictions, including identifying activities that should be performed during less sensitive time periods, depending on nearby use.
An evaluation of applicable state and local noise codes was provided as well as a review of the New Jersey Turnpike Authority's standard specification, subsection 104.11 pertaining to noise control. Recommended edits to the standard specification were provided, including a table of recommended noise level limits for each bridge structure. The report and criteria were prepared for and included within the Phase C submission.