Raritan River Drawbridge Replacement Project

Project Description

Paul Carpenter Associates, Inc. (PCA) conducted a transit noise and vibration impact assessment associated with the Raritan River Drawbridge Replacement project, in accordance with Federal Transit Administration (FTA) guidelines and procedures. Project improvements included complete replacement of the existing two-track moveable bridge with a new two-track bridge on an alignment to the west, built parallel to, and within close proximity of the existing Raritan River Drawbridge. The project also increased operable speeds on the bridge, relative to both pre-and post-Superstorm Sandy conditions.

Noise and vibration screening procedures for a commuter rail station, outlined within the FTA's Transit Noise and Vibration Impact Assessment guidance manual (FTA-VA-90-1003-06, May 2006), were implemented. No vibration-sensitive land use exists within applicable screening distances. However, a General Assessment was performed to determine the potential for operational noise impacts. Existing noise exposure for all analysis locations was determined through field measurements at representative sites. Since the existing bridge carries both commuter rail traffic and freight rail, and the project would increase operable speeds for both vehicle types, the impact evaluation was performed utilizing the Federal Railroad Administration's (FRA) CREATE Rail Noise Model. Due to the alignment shift away from noise-sensitive receptors, project-related noise levels were not anticipated to increase existing noise exposure levels.

Due to the proximity of existing noise and vibration sensitive land use to project improvements and an estimated 36-month construction timeline, FTA Noise and Vibration General Assessments of construction-related impacts were performed. The heaviest operations during the three main stages of construction were evaluated, including sheet driving/pier installation with a vibratory hammer, steel removal with shears, and track installation. Impacts were predicted to occur at the future site of the 2nd Street community park in Perth Amboy; however, a commitment has been made through community relations, in which the park will not be occupied during construction in order to preclude impact. Impact areas, within which vibration-induced structural damage and annoyance during sheet driving and pier installation could be expected, were computed based on FTA's reference data and propagation equations. No structures or vibration-sensitive land use are within the identified impact areas.

Middlesex County is in CO attainment, PM2.5 maintenance and O3 nonattainment. Since the project was listing in an approved Statewide Transportation Improvement Program (STIP) the project was exempt from regional air emissions modeling. Project-level conformity was addressed qualitatively since the rail service was not expected to increase as a result of the project.