National Academies Press: OpenBook

TR News September–October 2013: Environmental Sustainability in Transportation (2013)

Chapter: Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management

« Previous: Environmental Sustainability in Transportation: Recycling Materials and Techniques to Improve Sustainability: Delaware Department of Transportation s Model
Page 32
Suggested Citation:"Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
×
Page 32
Page 33
Suggested Citation:"Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
×
Page 33
Page 34
Suggested Citation:"Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
×
Page 34
Page 35
Suggested Citation:"Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
×
Page 35
Page 36
Suggested Citation:"Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
×
Page 36
Page 37
Suggested Citation:"Environmental Sustainability in Transportation: Soundscapes: A Sustainability Approach to Transportation Noise Management." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
×
Page 37

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

TR N EW S 28 8 SE PT EM BE R– O CT O BE R 20 13 32 Polcak is Senior Transportation Engineer, Maryland State Highway Administration, Baltimore. Miller is Senior Vice President, Harris Miller Miller & Hanson, Inc., Burlington, Massachusetts. The goal of environmental sustainability pre-sents new challenges to traditional notions ofhow transportation systems and their com- ponents affect the quality of life. For transportation noise control, the shift to planning for sustainability advances the concept of the soundscape or sound environment. In this context, the quality of life is improved to the extent that the soundscape is deemed desirable—that is, appropriate for the loca- tion and the associated activity. Traditional noise control strategies focus on one sound source at a time and target the intensity or loudness of that source. In contrast, the evaluation of a soundscape considers a multitude of sources and the desirability of their combinations. Transportation design requires standards or guidelines, but few metrics are associated with soundscape desirability. To pursue desirable sound- scapes as part of the transportation planning process, policy makers, engineers, and design professionals will need to understand subjective judgments about the sonic environment. Soundscape considerations are likely to alter the analysis and design processes, particularly in relation to noise barriers, quieter pave- ment, and source reduction. Role of Soundscapes The “triple bottom line” for sustainability requires a transportation project that is economical, environ- mentally friendly, and improves the quality of life. All transportation modes create some level of noise for those living in the vicinity. Improvements to the soundscape must address not only the undesirable aspects of noise produced by transportation but also the preservation or restoration of the desirable sounds that are covered up or masked by trans- portation noise. For transportation improvements or expansions to achieve the triple bottom line, the full panoply of sounds must be considered, with the goal of preserving or restoring desirable soundscapes. The soundscape is the total sound environment “with emphasis on the way it is perceived and under- stood by the individual or by a society” (1). In other words, a proper analysis must understand a sound- scape’s subjective meaning for the individuals who experience it. Judgments of a soundscape may depend on its location and visual appearance (2), the type of activ- ity or activities that occur (3), and the observer’s per- sonal history, expectations, emotional reaction, culture (4), and age (5). Evaluating this multiplicity of factors so that decisions can be made about sound- scape improvement or preservation is a formidable challenge. Noise Control A three-pronged approach has guided environmen- tal noise control and management and the noise reduction strategies for highway traffic (6): u Quieting the source, u Reducing noise along the path of transmission between the source and the receiver, and u Land use planning. The first two are direct abatement strategies that for a long time have been the foundation for effec- Soundscapes A Sustainability Approach to Transportation Noise Management K E N N E T H D . P O L C A K A N D N I C H O L A S P. M I L L E R Environmental Sustainability in Transportation Noise walls are a traditional option for noise control, but incorporating sustain - ability into planning requires evaluating an area’s soundscape. P H O TO : M A R Y LA N D SH A

TR N EW S 288 SEPTEM BER–O CTO BER 2013 33 tively reducing the impacts of noise in communities near transportation facilities. Whether the facility is a commuter rail line, an airport, or a major highway, the overarching efforts since the landmark environ- mental regulations of the early 1970s have focused on these two components in the approach to noise control. Which of the two yields the most benefits will depend on the particular mode of transportation involved and on the particular situation. Land use planning, the third prong in the approach to transportation noise control, may be viewed as a strategy of avoidance, as opposed to abatement. For example, prohibiting new residential development along a major Interstate highway will avoid a noise impact scenario; the goal is to promote or allow only development or activity that is com- patible with the level of noise in an area. Noise abate- ment, in contrast, would require a noise barrier for the new residential development along the Interstate. In applying the concept of soundscape to the abate- ment of highway traffic noise, the focus is less on the physical reduction in the level of noise and more on how the traffic noise is perceived as a component of the sonic environment. With the trend to sustainable development and sustainability, new developments tend to be more compact, urban-oriented environs, and the spaces that are created will have soundscapes that differ from those in the more traditional living spaces that characterize many suburban or rural envi- ronments. In either case, the totality of the sonic envi- ronment and the context of the various sounds indigenous to the area may be viewed in terms of their contribution to the quality of the environment. Quieting the Source Automobile and truck industry efforts have made steady progress in quieting the source. The primary subsources of noise from highway vehicles—the engine, the exhaust, and the drive train—have undergone technological advances and design improvements in the past 20 to 30 years that have resulted in some noise reductions. With these advances and increasingly stringent vehicle noise standards, a clear trend to quieter vehicles—partic- ularly in heavy trucks—is emerging in the fleet. In addition, the development of alternative-fuel vehicles—for example, hybrid and electric—has achieved a new level of quieting at the source. Design modifications to truck engine enclosures, improved muffler systems, and other redesigned vehicle com- ponents also have yielded noise reductions. Tire–pavement interaction is another major sub- source of noise from highway vehicles—it is the pri- mary source of traffic noise for most roads and for most vehicles at speeds above 30 mph (7). Although the physical quieting of many vehicle components has been accomplished gradually and through attri- tion—with older, noisier vehicles being replaced— quieter pavement technology has developed only recently. A quieter pavement surface can result in imme- diate reductions or alterations of source noise. Qui- eter pavements perhaps are not an alternative to traditional noise barriers but offer an additional option in the noise control arsenal, despite issues with the longevity and durability of their quieting aspects. As it crosses over the campus of the Illinois Institute of Technology in Chicago, a train on the Green Line travels through a noise barrier. PH O TO : K EN N ET H SP EN C ER , FL IC K R

TR N EW S 28 8 SE PT EM BE R– O CT O BE R 20 13 34 Influencing Perception These efforts at quieting or altering the character of particular sources or subsources of noise are impor- tant to the soundscape approach. Traditional noise abatement seeks to reduce offending or unwanted sounds according to established numerical criteria or limits; in contrast, the soundscape approach focuses on the human perception of the acoustic environ- ment and on “sounds of preference” (8) that con- tribute to human enjoyment or well-being—that is, to quality of life. Because the soundscape concept focuses on the identification, perception, and characterization of sounds in the total aural environment, the ability to alter the character of the contributing sounds pre- sents an opportunity to influence the perception of the sound or noise in a positive way. In an environ- ment in which multiple sources may contribute to the overall sound energy, the perception of domi- nant sounds, which are judged as negative or unde- sirable, and of sounds that are masked or overwhelmed complicates assessments of an indi- vidual’s annoyance or satisfaction. For example, human-made sounds—such as traf- fic noise—that mask the natural or desirable sounds indigenous to an area or community would typically be viewed as degrading the environment. Sounds are processed differently according to an individual’s cul- ture or experience, so that the same acoustical event can yield different meanings and interpretations, depending on the situation (9). Path Control Noise reduction at the source or subsource level can be effective, depending on the transportation mode. Reductions in the overall noise effects of aircraft, for example, have resulted principally from design improvements to the engine and airframe to quiet noise, as well as from operational modifications dur- ing take-offs and landings. In contrast, highway traf- fic noise abatement has relied on noise barriers as the primary and most effective approach. As noted earlier, the concept of sustainability and sustainable development fosters a design philosophy and characteristics, conditions, and practices differ- ent from more traditional development scenarios. Suburban sprawl—that is, suburban development that is centered on the single-lot, single-family dwelling—comes with a closer-to-nature atmosphere of open space, wooded areas, and backyards. Noise barriers target the single primary noise source—for example, an adjacent highway—and provide a means of restoring or improving the sound- scape by reducing the intrusive and typically domi- nant traffic noise and by simultaneously unmasking other desirable natural sounds in the community, such as birdsong or rustling leaves. Although not eliminated, the traffic noise can be relegated to a background component. In a sustainable development scenario, however, a more urbanized, compact approach to housing, along with a more pedestrian and public transit ori- entation, fosters greater use of public spaces, pro- ducing a more complex soundscape. Multiple sound sources affect audibility and may vary in time and duration, making the assessment of the soundscapes’ contribution to the quality of life challenging and complex. An assessment must include not only the A-weighted sound pressure level but also the link with psychoacoustic parameters to accommodate the multidimensional nature of perception (10). Acceptable Noise For soundscapes, the context or prevailing environ- ment can have a substantial effect on how a particu- lar sound is perceived. For example, a study of a major urban district in Kyoto, Japan, found that traf- fic noise was generally considered a positive sign of commercial activity, and rarely was characterized as an annoyance (11). Would traditional noise abate- ment strategies yield substantial benefits? In a sub- urban or rural context, that same traffic noise more likely would be viewed negatively, and abatement measures would be highly valued. As the example suggests, inhabitants of more urbanized places may perceive transportation noise as less of an annoyance and perhaps more acceptable within the soundscape. As a result, the desire for transportation noise abatement in urban settings may be expected to be reduced or at least altered, depend- ing on the characteristics of the area. In addition, the physical parameters of the devel- opment—for example, the presence of multistory, high-rise residences—may preclude the effective use PH O TO : C H R IS C A PE LL , FL IC K R P H O TO : M ILB O R N EO N E, W IK IM ED IA C O M M O N S A soundscape approach masks transportation noise while allowing desirable sounds, like those of the natural environment, to be heard. Design modifications such as turbine chevrons can decrease aircraft noise.

TR N EW S 288 SEPTEM BER–O CTO BER 2013 35 of such traditional abatement measures as noise bar- riers, although absorptive or quieter pavements may be effective in reducing the prominence or at least in altering the character of the traffic noise. Assessing Community Impact In the suburban setting, the traditional approach to traffic noise abatement is focused on substantially reducing the noise level from the highway source. In the majority of circumstances, this approach will yield meaningful and beneficial results for the com- munity. But when the soundscape is more complex and varied, with both positive and negative contrib- utory sources, additional attention may be needed to preserve or enhance the soundscape according to the community’s preferences. An assessment of the total soundscape, beyond the numerical noise levels, would be informative. This more integrated approach would require more effort in assessing community impacts. Studies on soundscapes often involve surveys and question- naires that probe the attitudes, expectations, and preferences of the community residents. The studies have found that the context of the various sounds, including both visual and sonic cues, has a major effect on the judgment of sound quality. Soundscape studies also can involve laboratory-based experi- ments with recorded data and statistical analysis of feedback from study participants. Researching Soundscapes Research comparing field measurements of quieter pavements has revealed that shifts away from the higher frequencies, to which the human ear is more sensitive, could translate into a more positive rating or perception of traffic noise as a component of the soundscape. Similarly, changes in the frequency char- acteristics of the traffic noise that reflects or echoes off of a building facade or other structure also could affect the perception. These shifts in frequency often are perceived as a change in the character of the noise source. In 2004, a laboratory-based soundscape experi- ment explored perceptions of the effects of a roadside traffic noise barrier (12). Participants listened to recordings of conditions before and after a roadside noise barrier was built and were asked to determine if the randomly selected sounds were with or with- out the noise barrier. In addition, participants were asked to describe the cues they used to discriminate between the with-barrier and without-barrier sam- ples. The results indicated that the noise barrier caused perceivable changes in the soundscape and that the changes could be interpreted as positive (13). The primary finding was that the noise barrier made the traffic noise in the soundscape more homogeneous, or less variable, which in general is perceived as more desirable. The noise barrier reduced higher fre- quency sound but made difficult the identification of single vehicle pass-bys and of changes in direction- ality—that is, the perceived relative position of sin- gle vehicles and their direction of movement. Land Use and Soundscapes The consideration of prevailing environmental noise conditions in land use planning—the third prong in noise reduction strategy—seeks to design or direct development compatible with the prevailing noise environment. The strategy is an exercise in avoid- ance—that is, avoiding the introduction of noise- sensitive activities into an already noisy environ - ment. The approach also tends to focus on the neg- ative aspects of the sonic environment and does not seek to change it but to adapt to it. In applying the concept of the soundscape, the goal is to improve the relationship between the aural space and the people in the living environment (13). The soundscape approach includes management of the elements of the acoustic environment that are of high quality and value to people, either through acoustic design or by management of the outdoor space, much in the same way that landscape design is applied to improve visual perception of the envi- ronment (8). Crafting Soundscapes In summary, sustainable development practices require the consideration and assessment of how the In Kyoto, Japan, and other areas, traffic noise is perceived as a sign of a healthy economy and rarely is considered an annoyance. P H O TO : V ILLE M ISA K I, F LIC K R

TR N EW S 28 8 SE PT EM BE R– O CT O BE R 20 13 36 physical effects of traditional traffic noise control measures affect the soundscape as a whole. The con- sideration of soundscape as a gauge of environmen- tal quality, however, has an inherent complication— multiple variables, contextual and subjective, influ- ence individuals’ perceptions of the sonic environ- ment (9). The context therefore includes cultural and personal preferences, sensitivities, and attitudes. An improvement in the soundscape does not involve noise level reduction only (9). The challenge is to craft meaningful and effective links between the tangible—sound levels and decibel values—and the intangible, multidimensional nature of human per- ception. References 1. Truax, B. (ed.) Handbook for Acoustic Ecology. ARC Pub- S oundscapes are complex. A soundscape is the all-encom-passing, audible environment experienced in a specific location. In considering a soundscape’s effect on quality of life, the question to answer is “How can the soundscape be judged in a way that will facilitate improvement?” Improving Soundscapes For decades, efforts to improve soundscapes have focused on noise control, treating a single source at a time, seeking improve- ment by minimizing annoyance, limiting noise as quantified by a single noise metric, such as the day–night sound level or the community noise equivalent level. This approach has been suc- cessful, so that fewer numbers of residents are exposed to higher noise levels and presumably experience less annoyance. But consideration of the entire soundscape needs to address multiple sources, some undesirable, some desirable. The noise control approach focuses on one undesirable source at a time and does not consider desirable sounds or judge which undesirable sound most needs quieting. Improving soundscapes means reduc- ing the noise from undesirable sources and permitting the desir- able ones to be heard. Judging Soundscapes Just as the concept of annoyance has been used to summarize the multiple adverse effects of transportation noise on people, a simplifying subjective judgment may emerge to summarize the human factors, experiences, and emotions that influence a person’s reaction to a soundscape. For instance, a sound- scape’s contribution to quality of life could be summarized by rating the components of the soundscape on a scale of desir- ability. One method of collecting this information is to survey res- idents to identify the sounds they hear and to rate each sound. Desirability could serve as the rating scale, ranging from –4 or extremely undesirable to +4 or extremely desirable. Figure 1 (page 37) shows hypothetical results from a survey of resi- dents that readily distinguishes the sounds people like and those they do not. The values are cumulative, moving from undesirable at the left to desirable at the right. The more rapidly the cumulative value increases, the less desirable is the sound. Birdsong is desirable for most people, but most rate road traffic noise as undesirable. The author is Senior Vice President, Harris Miller Miller & Hanson, Inc., Burlington, Massachusetts. Judging Soundscapes N I C H O L A S P. M I L L E R An example of a video for use in laboratory sound tests can be found on You Tube—see footnote on page 37. A 2004 study showed that noise walls reduce higher- frequency sounds and cause traffic noise to be perceived as more homogeneous. P H O TO : M A R Y LA N D SH A

TR N EW S 288 SEPTEM BER–O CTO BER 2013 37 lications, Vancouver, British Columbia, Canada, 1978. 2. Adams, M., T. Cox, G. Moore, B. Crawford, M. Refaee, and S. Sharples. Sustainable Soundscapes: Noise Policy and the Urban Experience. Urban Studies, Vol. 43, No. 13, Decem- ber 2006, pp. 2385–2398. 3. Yu, L., and J. Kanga. Effects of Social, Demographical and Behavioral Factors on the Sound Level Evaluation in Urban Open Spaces. Journal of the Acoustical Society of America, Vol. 123, No. 2, February 2008, p. 772. 4. Dubois, D., C. Gustavino, and M. Raimbault. A Cognitive Approach to Urban Soundscapes: Using Verbal Data to Access Everyday Life Auditory Categories. Acta Acustica United with Acustica, Vol. 92, 2006, pp. 865–874. 5. Yang, W., and J. Kang. Soundscape and Sound Preferences in Urban Squares: A Case Study in Sheffield. Journal of Urban Design, Vol. 10. No. 1, February 2005, pp. 61–80. 6. Highway Traffic Noise: Analysis and Abatement Guidance. FHWA-HEP-10-025, Federal Highway Administration, December 2011. 7. Rasmussen, R. O., R. J. Bernhard, U. Sandberg, and E. P. Mun. The Little Book of Quieter Pavements. FHWA-IF-08- 004, Federal Highway Administration, July 2007. 8. Brown, A. L. Soundscapes and Environmental Noise Man- agement. Noise Control Engineering Journal, Vol. 58, No. 5, September–October 2010, pp. 493–500. 9. Schulte-Fortkamp, B. The Application of Soundscape in Community Noise. Proceedings of Inter-Noise 2007, Istan- bul, Turkey, 2007. 10. Genuit, K., B. Schulte-Fortkamp, and A. Fiebig. Psycho - acoustic Mapping Within the Soundscape Approach. Pro- ceedings of Inter-Noise 2008, Shanghai, China, 2008. 11. Finegold, L. S., and K. Hiamatsu. Linking Soundscapes with Land Use Planning in Community Noise Manage- ment Policies. Proceedings of Inter-Noise 2003, Seogwipo, Korea, 2003. 12. Nilsson, M. E., T. Kaczamarek, and B. Berglund. Perceived Soundscape Evaluation of Noise Mitigation Methods. Pro- ceedings of Inter-Noise 2004, Prague, Czech Republic, 2004. 13. Lercher, P. Soundscape Research, Quality of Life, and Health: An Integrated Environmental Health Viewpoint. Proceedings of Inter-Noise 2007, Istanbul, Turkey, 2007. Guidance for Action Two additional questions need to be asked about the ratings in Figure 1: u What are the objective sound levels from each source that each respondent is rating? u For each source, what is the threshold sound level sepa- rating an undesirable rating from a desirable rating? The answers can provide noise control design goals for each source. The type of data shown in the figure could be acquired through a mail survey, but important questions would remain unanswered: u Are all respondents hearing the same sounds? u What are the levels of the sounds that respondents hear? u What time of day, week, or year do the ratings represent? Proper identification of the respondent’s location—and careful survey wording—could resolve some of these ques- tions, but determining objective sound levels for each source for each person is an expensive and complicated, if not impos- sible, proposition. Laboratory Trials Although collecting desirability ratings and sound levels in situ would be the gold standard for soundscape analysis, lab- oratory studies could associate human reactions to sound- scapes with metrics of sound. Researchers have had success bringing an outdoor experience into a laboratory setting to judge outdoor sounds. The technique of using various combi- nations of audio and visual reproductions in the laboratory has yielded subjective evaluations that correlate closely with eval- uations made in the field. Laboratory tests could employ high-definition videos and high-quality sound to learn how people rate the components of different soundscapes, and to test the correlation of vari- ous sound metrics with the ratings.1 The soundscapes would be constructed in the laboratory setting, from separate record- ings of individual sources and of different ambient back- grounds. Patching the soundscapes together would permit accurate determination of the sound metrics of each con- tributing source—a disaggregation not always possible with in situ measurements. Laboratory results, especially acquired from subjects who are not familiar with a specific soundscape, may differ from the results that derive from people who live within that sound- scape. But work in the laboratory could help develop a gen- eral understanding of how people subjectively evaluate different soundscapes and the component sound sources and could test the utility of different noise metrics. 1An example has been uploaded to http://youtu.be/NjOIfUrFcR8. Listen with high-quality headphones for full effect. FIGURE 1 Respondent ratings of three sounds in a selected location or neighborhood: extremely undesirable to extremely desirable.

Next: Environmental Sustainability in Transportation: Noise and Natural Sounds in America s National Parks »
TR News September–October 2013: Environmental Sustainability in Transportation Get This Book
×
 TR News September–October 2013: Environmental Sustainability in Transportation
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

This issue of the TR News focuses on environmental sustainability in transportation and how it can help improve the quality of life for individuals and communities. Articles highlight practice-ready research and cover such topics as integrating vegetation and green infrastructure into sustainable transportation planning; implementing the Eco-Logical approach in Nevada, Colorado, Utah, Montana, Washington, and Oregon; Virginia's improved construction specifications for stormwater pipe-lining materials; creating a multiagency sustainability framework in Colorado; effective noise barriers in North Carolina; Delaware's use of recycling materials and techniques; sustainability in airspace system planning; and more.

The September-October 2013 issue of TR News includes the following articles:

Environmental Sustainability in Transportation: Improving the Quality of Life

Evaluating Sustainable Development: A Quality-of-Life Focus for Transportation Decision Making

Integrating Vegetation and Green Infrastructure into Sustainable Transportation Planning

Eco-Logical in Practice: Implementing an Ecosystem-Based Approach, Streamlining Environmental Processes for Transportation Projects

Soundscapes: A Sustainability Approach to Transportation Noise Management

Sustainability in Airspace System Planning

Research Pays Off: Reclaimed Asphalt Pavement with Steel Slag Aggregate: Successful Use in Illinois Pavements

The TR News is TRB's bimonthly magazine featuring timely articles on innovative and state-of-the-art research and practice in all modes of transportation. It also includes brief news items of interest to the transportation community, research pays off articles profiles of transportation professionals, workshop and conference announcements, new book notices, and news of TRB activities. Submissions of manuscripts for possible publication are accepted at any time.

Copies of the TR News may be purchased individually or ordered on an annual subscription basis.

READ FREE ONLINE

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!