Cover Image

Not for Sale



View/Hide Left Panel
Click for next page ( 244


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 243
Project alignment, both horizontal and vertical; Topography; System operation plan; Vehicle technology (e.g., light rail transit [LRT], diesel multiple unit [DMU]); Land use characteristics and location; and Demographic information (same as for Method 2). Results and their presentation. Results of transit noise projects are sometimes presented as tables listing neighborhoods with impacted sites, including number of residences. This information may be obtained by specifically analyzing each neighborhood individually or by drawing project impact contours on maps. The primary result is to document the number of impacted properties. Results of the distributive effects assessment can be presented using the techniques described in Method 2. Assessment. Graphical presentations of noise impacts usually include maps with boundaries showing where impacts occur. It is relatively simple to combine results with protected population information to assess environmental justice for transit projects, although data collection may be time consuming in areas where environmental justice concern is high. If the project evaluation identifies an impact or severe impact, noise mitigation will need to be considered. Noise mitigation for transit projects includes more options than are available for a highway project. One key difference is that the source (i.e., train) can have mitigation measures applied directly to it. These may include wheel skirts, wheel damping to prevent squealing, and a special configuration of the vehicle to hide mechanical devices, such as air conditioners, under the vehicle. Mitigation measures may also include greasing tracks at curves to prevent squealing or building barriers in the form of walls or earthen berms to block the line of sight. The impacts of any mitigation measures would need to be considered, including the detrimental effect of applying grease to tracks and the potential security and loss of visibility due to barriers. RESOURCES 1) Federal Highway Administration (FHWA). 1995. Highway Traffic Noise and Abatement Policy and Guidance. Washington, DC: United States Department of Transportation. The Federal Highway Administration's site on highway traffic noise provides links to numerous resources, including the highway traffic noise guide for 1995. The information can be found at http://www.fhwa.dot.gov/environment/noise. In addition, the FHWA procedures for traffic noise analysis and abatement are described in 23 CFR 772, available at http://www.fhwa.dot.gov/legsregs/directives/fapg/cfr0772.html. 2) Federal Transit Administration (FTA). 1995. Transit Noise and Vibration Impact Assessment. Washington, DC: U.S. Department of Transportation. Much of the information used to describe the Transit Project Noise Analysis method is from the FTA's Transit Noise and Vibration Impact Assessment guide. The entire document is 248