The I-80 Parsippany - Troy Hills Roadway Improvements project is located in one of northern New Jersey's busiest and most congested areas. The Project encompassed three interchanges formed with I-80 through Parsippany - Troy Hills, Morris County: I-80 Interchange 42 with US 202-Cherry Hill Road/Littleton Road; I-80 Interchange 43 with I-287; and I-80 Interchange 45 with CR 637 - South Beverwyck Road. Proposed improvements of this project addressed safety, operational, and maintenance issues at these interchanges.
Paul Carpenter Associates, Inc. (PCA) completed air quality and noise sections of the New Jersey Department of Transportation (NJDOT) Categorical Exclusion Document (CED) and conducted a noise analysis related to the proposed improvements. Proposed improvements included modifications to roadway geometry, drainage, signing, and traffic signals as well as pavement rehabilitation from milepost 41.42 to 45.63.
A Noise Measurement Study was conducted in twelve locations to identify peak noise levels. Based on monitored noise levels, roadway geometry information, and existing traffic volumes, the FHWA TNM2.5 was validated for Year 2030 modeling. Under the Year 2030 Build conditions, impacts were evaluated and noise mitigation was investigated. Due to the need to remove portions of two existing noise walls, two "in-kind" replacement noise walls were assessed. Additionally, one new cost-effective noise wall was designed.
PCA also completed a Final Noise Study for the proposed project using final design geometry. Two building attenuation studies were performed at schools to identify both interior noise levels as well as levels of window-wall attenuation. This information was utilized to determine whether air conditioning was necessary to mitigate traffic noise impact. Exterior and concurrent interior noise measurements were documented within the closest classrooms to I-80 during peak morning travel periods. Results of the studies concluded that one of the two schools possessed interior noise levels higher than allowable noise criteria. Therefore, PCA recommended air conditioning units for a total of four classrooms within the school in order to mitigate project-related noise impacts.
PCA investigated ten potential noise walls. Three noise walls were found to be feasible and reasonable (two "replace-in-kind" and one new wall) in accordance with NJDOT policy. A public meeting was held to discuss the project and recommended mitigation measures and obtain resolutions from appropriate parties in support of the recommended noise walls.