01054177

Component

This paper describes how the Central Artery/Tunnel (CA/T) Project in Boston, Massachusetts, is the largest and most technically challenging highway and urban reconstruction project in American history. Otherwise known as the Big Dig, the project’s scope includes extending the Massachusetts Turnpike (I-90) through a new tunnel under Boston Harbor to Logan Airport, replacing old bridges and ramps over the Charles River with a new cable-stayed bridge, relocating the Central Artery (I-93) traffic into new tunnels under downtown Boston, and removing the old elevated Artery to reunify city neighborhoods. At a total estimated cost of $14.6 billion, the project promises many traffic and socio-economic benefits for the residents and business owners in Boston as well as for the entire New England region. As the CA/T Project nears completion, many of the highly anticipated benefits of the project are finally coming to fruition. One interesting example is that the background noise in the city has been noticeably reduced since the I-93 Artery traffic was relocated underground. But how much quieter has it gotten, and what are the implications to the CA/T Project’s construction noise policies which are based on relative noise criteria? Might the remaining construction noise not be masked as well by the quieter background condition, and if so, will the residents and business owners start complaining more about noise from the remaining construction work? This paper summarizes the subjective reaction that Bostonians had to the surprisingly quieter conditions that resulted when the old elevated I-93 Artery traffic was relocated underground. Quantitative evidence is provided comparing many years-worth of community noise measurements collected in the Downtown and North End sections of the project. The results show that background L90 noise levels in areas of the city close to the highway project reduced by over 4 dBA during the daytime, and by over 6 dBA during the evening and nighttime, due to the relocation of I-93 Artery traffic underground. This paper summarizes the considerations and policy decisions made by CA/T Project officials with respect to potentially changing the contractors’ construction noise control specifications to accommodate the quieter background noise condition, as well as the project’s strategy for responding to potential additional construction noise complaints from the public.

01054353

English

pp 406-416

2004

Noise-Con 04. The 2004 National Conference on Noise Control Engineering

CD-ROM

Figures; Photos; References (5) ; Tables (1)

Arterial highways; Noise barriers; Noise control; Noise sources; Reconstruction; Sound transmission; Traffic noise; Tunnels; Underground structures

Central Artery/Tunnel Project

Boston (Massachusetts)

Bridges and other structures; Energy; Environment; Highways; I15: Environment

TRIS, TRB

Jul 19 2007 10:53AM