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Appendix C Noise and Vibration Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 1 APPENDIX C. NOISE AND VIBRATION ANALYSIS C.1 Introduction & Project Description The Massachusetts Executive Office of Transportation (EOT), in conjunction with the Pioneer Valley Planning Commission (PVPC), Vermont Agency of Transportation (Vtrans), Pan Am Southern Railroad (PAS), and Amtrak, is proposing to relocate the Amtrak intercity passenger train, known as the Vermonter, from the New England Central Railroad back to its former route on the Pan Am Southern Railroad between Springfield and East Northfield in Massachusetts. The Vermonter operates daily between St. Albans, Vermont and Washington, D.C. The routing of the Vermonter in Vermont and south of Springfield would remain unchanged. It is anticipated that initial service would include station stops at the former Amtrak station at Northampton and the new intermodal station at Greenfield, with a potential for additional stations in the future. The project would include improvements to the the existing Pan Am Southern rail line, including crosstie replacement, rail replacement, rehabilitation of grade crossings, reactivation of passing sidings and portions of double track, upgrading of switches, improvements to signal and communications systems, surfacing and alignment of track, and improvements to bridges and station platforms. The Project improvements would occur within the existing right-of-way owned by the Pan Am Southern. The Project does not involve any acquisition of additional right-of-way. The Proposed Project does not involve any additional ballast or fill material to be placed beyond the existing limits of ballast or fill. As such, there would be no culvert repair or replacement. There will be no in-water work in federal or state regulated wetlands or waterways. The Project does not involve clearing or grading activity. The proposed project has potential to change noise and vibration emissions from trains in the corridor. Therefore, noise and vibration analyses were performed using using guidelines published by the Federal Railroad Administration (FRA) and Federal Transit Administration (FTA). The analyses evaluated noise and vibration from trains under existing and future conditions. C.2 Regulatory Requirements The proposed project is subject to environmental review requirements of the National Environmental Policy Act (NEPA). C.3 Technical Approach Federal Railroad Administration (FRA) and Federal Transit Administration (FTA) methodologies were used to assess noise and vibration associated with the proposed project. Spreadsheet models were used to estimate existing noise levels, determine noise impact thresholds, calculate wayside noise levels (the noise due to a train pass-by event), and to Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 2 calculate locomotive horn noise levels at public at-grade crossings. The FRA grade crossing database was used to identify potential public at-grade crossings in the project area. That database was refined based on project plans and information collected during the preparation of this environmental assessment. Geographic Information System (GIS) technology was used extensively to evaluate spatial relationships between the rail line and noise-and vibrationsensitive land uses in the project area, and also to evaluate population density – in an assessment of existing noise levels. The proposed project will result in the relocation of a passenger train. Noise and vibration effects of the passenger train in the current corridor will be eliminated; this is a benefit of the proposed project. Noise and vibration analyses described in this technical memorandum do not quantify the net benefit of relocating the passenger service to a different project corridor, yet the benefit is recognized to occur. C.4 Assessment of Noise This section discusses the methodology and potential impacts related to the operational airborne noise from the proposed Knowledge Corridor Project. The noise analysis followed Federal Transit Administration (FTA) guidelines published in ―Transit Noise and Vibration Impact Assessment‖ (May 2006). The project team performed a Noise Screening Assessment and a General Noise Assessment in accordance with FTA guidelines to assess project-related airborne noise. Human Perception Levels Sound travels through the air as waves of tiny air pressure fluctuations caused by vibration. In general, sound waves travel away from the noise source as an expanding spherical surface. As a result, the energy contained in a sound wave is spread over an increasing area as it travels away from the source, resulting in a decrease in loudness at greater distances from the noise source. Noise is typically defined as unwanted or undesirable sound. The intensity or loudness of a sound is determined by how much the sound pressure fluctuates above and below the atmospheric pressure and is expressed in units of decibels. The decibel (dB) scale used to describe sound is a logarithmic scale that accounts for the large range of sound pressure levels in the environment. By using this scale, the range of normally encountered sound can be expressed by values between 0 and about 140 dB. Sound-level meters measure the actual pressure fluctuations caused by sound waves and record separate measurements for different frequency ranges. Most sounds consist of a broad range of sound frequencies, from low frequencies to high frequencies. The average human ear does not perceive all frequencies equally. Therefore, the A-weighting scale was developed to approximate the way the human ear responds to sound levels; it mathematically applies less ―weight‖ to frequencies we don’t hear well, and applies more ―weight‖ to frequencies we do hear well. Typical A-weighted noise levels for various types of sound sources are summarized in Figure 1 (Typical A-Weighted Sound Levels). Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 3 Figure 1 Typical A-Weighted Sound Levels Source: FTA, ―Transit Noise and Vibration Impact Assessment‖ (May 2006) The equivalent sound level (Leq) is often used to describe sound levels that vary over time, usually a one-hour period. The Leq is considered an energy-based average noise level. Using twenty-four consecutive 1-hour Leq values it is possible to calculate daily cumulative noise exposure. The descriptor used to express daily cumulative noise exposure is the Day-Night Sound Level (Ldn). The Ldn includes a 10-dBA penalty imposed on noise that occurs during the nighttime hours (between 10 PM and 7 AM) where sleep interference might be an issue. The 10-dBA penalty makes the Ldn useful when assessing noise in communities. The Sound Exposure Level (SEL) combines the equivalent sound level with the duration of an event to determine the total amount of noise exposure. The logarithmic nature of dB scales is such that individual dB levels for different noise sources cannot be added directly to give the noise level for the combined noise source. For example, two noise sources that produce equal dB levels at a given location will produce a combined noise level that is 3 dBA greater than either sound alone. When two noise sources differ by 10 dBA, the combined noise level will be 0.4 dBA greater than the louder source alone. People generally perceive a 10-dBA increase in a noise level as a doubling of loudness. For example, a 70-dBA sound will be perceived by an average person as twice as loud as a 60-dBA sound. People generally cannot detect differences of 1 dBA to 2 dBA. Differences of 3 dBA can be detected by most people with average hearing abilities. A 5-dBA change would likely be perceived by most people under normal listening conditions. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 4 When distance is the only factor considered, sound levels from isolated point sources of noise typically decrease by about 6 dBA for every doubling of distance from the noise source. When the noise source is a continuous line (for example, vehicle traffic on a highway), noise levels decrease by about 3 dBA for every doubling of distance away from the source. Noise levels at different distances can also be affected by factors other than the distance from the noise source. Topographic features and structural barriers that absorb, reflect, or scatter sound waves can increase or decrease noise levels. Atmospheric conditions (wind speed and direction, humidity levels, and temperatures) can also affect the degree to which sound is attenuated over distance. Reflections off topographical features or buildings can sometimes result in higher noise levels (lower sound attenuation rates) than would normally be expected. Temperature inversions and wind conditions can also diffract and focus a sound wave to a location at considerable distance from the noise source. As a result of these factors, the existing noise environment can be highly variable depending on local conditions. Noise Evaluation Criteria The FTA established procedures and guidelines for assessing noise impacts. The noise descriptors most often used for transit noise evaluations are the dBA, the Leq and the Ldn. The FTA impact criteria are used to estimate existing noise levels and future noise impacts from transit operations. The land use classifications applicable to transit projects are shown in Table 1 (Land Use Categories and Metrics for Transit Noise Impact Criteria). The Ldn descriptor is used to assess transit-related noise at residential and land uses where overnight sleep occurs. The Leq descriptor is used to assess transit-related noise at other land uses. The FTA noise impact criteria are defined by two curves, severe and moderate, which are defined below. Severe Impact. A significant percentage of people are highly annoyed by noise in this range. Noise mitigation would normally be specified for severe impact areas unless it is not feasible or reasonable (unless there is no practical method of mitigating the impact). Moderate Impact. In this range, other project-specific factors are considered to determine the magnitude of the impact and the need for mitigation. Other factors include the predicted increase over existing noise levels, the types and number of noise-sensitive land uses affected, existing outdoor-indoor sound insulation, and the cost-effectiveness of mitigating noise to more acceptable levels. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 5 Table 1 Land-Use Categories and Metrics for Transit Noise Impact Criteria Land-Use Category Noise Descriptor (dBA) Description of Land-Use Category 1 Outdoor Leq(h)a Tracts of land where quiet is an essential element in their intended purpose. This category includes lands set aside for serenity and quiet, and such land uses as outdoor amphitheaters and concert pavilions, as well as national historic landmarks with significant outdoor use. Also included are recording studios and concert halls. 2 Outdoor Ldn Residences and buildings where people normally sleep. This category includes homes, hospitals, and hotels where a nighttime sensitivity to noise is assumed to be of utmost importance. 3 Outdoor Leq(h)a Institutional land uses with primarily daytime and evening use. This category includes schools, libraries, and churches where it is important to avoid interference with such activities as speech, meditation, and concentration on reading material. Places for meditation or study associated with cemeteries, monuments, museums, campgrounds and recreational facilities can also be considered to be in this category. Certain historical sites and parks are also included. . Source: FTA, ―Transit Noise and Vibration Impact Assessment‖ (May 2006) a Leq for the noisiest hour of transit-related activity during hours of noise sensitivity. The FTA noise impact criteria are shown in Figure 2 (FTA Noise Impact Criteria) below. The figure illustrates existing noise exposure and project-related noise exposure, and demonstrates that FTA noise impact thresholds vary with existing noise levels. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 6 FIGURE 2 FTA NOISE IMPACT CRITERIA Methodology Airborne noise effects associated with the proposed Knowledge Corridor Project were evaluated using the FTA’s Noise Screening Assessment and General Noise Assessment methods (―Transit Noise and Vibration Impact Assessment,‖ May 2006). The project team identified noisesensitive land uses using digital aerial photographs, land use-related GIS files and internet searches. The Noise Screening Assessment looks for the presence of noise-sensitive land uses within FTA’s fixed, default screening distances. Results of the screening assessment confirmed the presence of noise-sensitive land uses within the default screening distance. Therefore a General Noise Assessment was performed. This methodology included identifying noise-sensitive land uses in the project corridor, estimating existing outdoor noise levels in the project area, using the existing noise levels to identify noise impact thresholds, calculating project-related outdoor noise levels, and determining if project-related noise levels exceed FTA noise impact thresholds. Existing outdoor noise levels were estimated in accordance with FTA guidelines presented in Chapter 5 of the guidance document (FTA, 2006). The existing noise exposure was calculated for each noise segment based on proximity to roads, rail lines and population density. The maximum representative noise level, calculated based on the receptors distance from roads, rail lines and population density was used as a representative existing noise level. Sound exposure levels (SEL) for project related noise sources were estimated using FTA reference values. Reference SEL’s used in the Knowledge Corridor noise analysis are shown in Table 2, and represent the estimated sound exposure level for a noise event measured at a distance of 50 feet from the track at a speed of 50 mph. The reference SEL for an idling Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 7 locomotive is also shown; this was used to assess noise from passenger trains idling in the stations. Table 2 Sound Exposure Levels used in the General Noise Assessment Noise Source Sound Exposure Level (SELref) Railcar Pass-by 82 dBA Locomotive Pass-by 92 dBA Idling Locomotive in a Station 109 dBA Audible Warning Signal (horn) 110 dBA The General Noise Assessment incorporated the following assumptions: Noise impact thresholds were based on the land-use category and the estimated existing noise level. The analysis assumed soft, absorptive ground, resulting in a ground factor G = 0.625 for ground attenuation, and ignored shielding effects. Table 3 presents the rail traffic information used in this analysis. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 8 Table 3. Rail Traffic Summary Information Current Proposed Freight Trains Daytime trains (7AM – 10 PM) 7 9 Nighttime trains (10PM – 7AM) 2 2 No. of Locomotives 1 or 2 1 or 2 No. of Cars 20-40 20-50 Speed (mph) 10 40 Passenger Trains Daytime trains (7AM – 10 PM) 0 2 Nighttime trains (10PM – 7AM) 0 0 No. of Locomotives 0 1 No. of Cars 0 5 Speed (mph) 0 60 Existing Noise Levels Existing outdoor noise levels were estimated in accordance with FTA guidelines. The existing noise exposure was calculated for each noise-sensitive receptor based on proximity to roads, rail lines and population density. The maximum representative noise level, calculated based on the receptors distance from roads, rail lines and population density was used as a representative existing noise level. For the purpose of the General Noise Assessment, the proposed Knowledge Corridor was separated into nine segments. The nine segments were selected to represent a range of existing noise conditions throughout the corridor. Six of the segments include the urban areas along the right-of-way. Two segments are areas where roadways are very near the rail right-of-way and their noise is assumed to dominate the ambient acoustic environment. The final segment consists of all the remaining areas, mostly rural, not included in the other segments. Using the methods described above, the existing noise exposures for each of the nine segments are presented in Table 4. The existing noise exposure for each noise segment was calculated by averaging the calculated existing noise levels for all receivers within the area. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 9 Table 4 Existing Noise Exposure in the Project Area Segment Name Dominant Existing Noise Source Existing Noise Exposure (dBA) Ldn Leq Day Greenfield Rail 64 56 Deerfield Rail 64 55 South Deerfield Rail 64 55 Northampton Rail 66 57 Holyoke Rail 64 57 Springfield Area Rail 66 58 Mt. Hermon Station Road Roadway /Interstate 69 68 Northampton Road Roadway /Interstate 65 63 Rural Areas Rail 64 55 Noise Analysis Results Table 5 presents the number of noise impacts per project segment. The table shows analysis results including severe and moderate noise impacts for each of the three land use categories used by FTA. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 10 Table 5 Summary of Impacted Receptors Project Segment Airborne Noise Impacts Severe Moderate Greenfield Category 1 0 0 Category 2 0 44 Category 3 0 3 Deerfield Category 1 0 0 Category 2 0 4 Category 3 0 2 South Deerfield Category 1 0 0 Category 2 0 14 Category 3 0 0 Northampton Category 1 0 0 Category 2 0 30 Category 3 0 1 Holyoke Category 1 0 0 Category 2 0 21 Category 3 0 1 Springfield Area Category 1 0 0 Category 2 0 1 Category 3 0 5 Northampton Road Category 1 0 0 Category 2 0 22 Category 3 0 1 Mt. Hermon Station Road Category 1 0 0 Category 2 1 4 Category 3 0 0 Rural Category 1 0 0 Category 2 1 49 Category 3 0 1 Total 2 203 Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 11 Analysis results project a total of 205 noise impacts due to the proposed project: 203 moderate noise impacts and 2 severe noise impacts. Both of the severe impacts result from horn noise where a Category 2 receptor lies very near the rail line. Creating new quiet zones at these two grade crossings could mitigate these predicted severe noise impacts; receiver-based treatments (i.e. new storm windows and storm doors with a high transmission loss, central air conditioning, etc.) could also be used to mitigate the severe noise impacts. Of the moderate impacts, 14 were impacts to Category 3 receptors and the remaining 189 were to Category 2 receptors. Based on the linear extent of the proposed project, and the number of urban areas it passes through, the number of moderate noise impacts is not unusal. There are no impacts to Category 1 receptors. Figure 3, at the end of this technical memorandum, shows the locations where noise impacts are predicted to occur. C.5 Assessment of Vibration This section summarizes the methodology and results of the vibration analysis. The Screening Vibration Assessment and General Vibration Assessment described here was prepared in accordance with FTA guidelines (―Transit Noise and Vibration Impact Assessment‖ (May 2006)) to estimate the number of potential ground-borne vibration impacts created by the proposed project. Human Response and Perception of Vibration Levels Ground-borne vibration can be a concern for residents or at facilities that are vibration-sensitive, such as laboratories or recording studios. The effects of ground-borne vibration include perceptible movement of building floors, interference with vibration sensitive instruments, rattling of windows, shaking of items on shelves or hanging on walls, and rumbling sounds. Vibration consists of rapidly fluctuating motions. However, human response to vibration is a function of the average motion over a longer (but still short) time period, such as one second. The root mean square (RMS) amplitude of a motion over a one second period is commonly used to predict human response to vibration. For convenience, decibel notation is used to describe vibration relative to a reference level. This analysis uses the unit of vibration decibels (VdB) relative to a reference of 10-6 inches per second (1 μin/sec) per FTA and FRA. In contrast to airborne noise, ground-borne vibration is not a phenomenon that most people experience every day. The background vibration level in residential areas is usually 50 VdB or lower—well below the threshold of perception for humans, which is around 65 VdB. Levels at which vibration interferes with sensitive instrumentation such as nuclear magnetic resonance (NMR) equipment and other optical instrumentation can be much lower than the threshold of human perception. Most perceptible indoor vibration is caused by sources within a building such as the operation of mechanical equipment, movement of people, or slamming of doors. Typical outdoor sources sources of perceptible ground-borne vibration are construction equipment, steel-wheeled trains, and traffic on rough roads. Vibration as it relates to railway movements is generally caused by uneven interactions between the wheels of the train and the railway surfaces. Examples of this include wheels rolling over rail joints and flat spots on wheels that are not true. These uneven interactions result in vibration that travels through the adjacent ground. This vibration can range from barely perceptible to very Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 12 disruptive. The following section provides a description of how vibration affects human activity, which is generally classified by land use categories. FTA Vibration Criteria The FTA recognizes three land use categories for assessing general vibration impacts. Land Use Category 1 – High Vibration Sensitivity: This category includes buildings where low ambient vibration is essential for operations within the building that may be well below levels associated with human annoyance. Typical Category 1 land uses include vibration-sensitive research and manufacturing facilities, hospitals, and university research operations. Category 1 also includes special land uses, such as concert halls, television and recording studios, and theaters, which can be very sensitive to vibration and ground-borne noise. The FTA has developed special vibration levels for these land uses. Land Use Category 2 – Residential: This category includes all residential land uses and any building where people sleep, such as hotels and hospitals. Land Use Category 3 – Institutional: This category includes schools, churches, other institutions, and quiet offices that do not have vibration-sensitive equipment, but still have the potential for activity interference. The criteria for ground-borne vibration (for a General Vibration Assessment) are shown in Table 6. The criteria for vibration and noise for Category 1 special buildings are shown in Table 7. Table 6 Ground-Borne Vibration Impact Criteria for General Vibration Assessment Land Use Category Ground-Borne Vibration Impact Levels (VdB re 1 micro inch/sec) Frequent Events1 Occasional Events2 Infrequent Events3 Category 1: Buildings where vibration would interfere with interior operations. 65 VdB4 65 VdB4 65 VdB4 Category 2: Residences and buildings where people normally sleep. 72 VdB 75 VdB 80 VdB Category 3: Institutional land uses with primarily daytime use. 75 VdB 78 VdB 83 VdB Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 13 Source: FTA, ―Transit Noise and Vibration Impact Assessment‖ (May 2006) (FTA-VA-90-1103-06), page 8-3. Notes: 1 ―Frequent Events‖ is defined as more than 70 vibration events per day. Most rapid transit projects fall into this category. 2 ―Occasional Events‖ is defined as between 30 and 70 vibration events of the same source per day. Most commuter trunk lines have this many operations. 3 ―Infrequent Events‖ is defined as fewer than 30 vibration events per day. This category includes most commuter rail branch lines. 4 This criterion limit is based on levels that are acceptable for most moderately sensitive equipment such as optical microscopes. Vibration-sensitive manufacturing or research would require detailed evaluation to define the acceptable vibration levels. Ensuring lower vibration levels in a building often requires special design of the HVAC systems and stiffened floors. Table 7 Ground-Borne Vibration and Noise Impact Criteria for Special Buildings Type of Building or Room Ground-Borne Vibration Impact Levels (VdB re 1 micro-inch/sec) Frequent Events1 Occasional or Infrequent Events2 Concert Halls 65 VdB 65 VdB TV Studios 65 VdB 65 VdB Recording Studios 65 VdB 65 VdB Auditoriums 72 VdB 80 VdB Theaters 72 VdB 80 VdB Source: FTA, ―Transit Noise and Vibration Impact Assessment‖ (May 2006) (FTA-VA-90-1103-06), page 8-4. Notes: 1 ―Frequent Events‖ is defined as more than 70 vibration events per day. Most transit projects fall into this category. 2 ―Occasional or Infrequent Events‖ is defined as fewer than 70 vibration events per day. This category includes most commuter rail systems. 3 If the building will rarely be occupied when the trains are operating, there is no need to consider impact. As an example, consider locating a commuter rail line next to a concert hall. If no commuter trains will operate after 7 p.m., the trains should rarely interfere with the use of the hall. Methodology A Screening Vibration Assessment was performed to determine if any vibration-sensitive land uses exist within FTA’s fixed, default vibration screening distances. Results of the screening assessment confirmed the presence of vibration-sensitive land uses within FTA’s screening Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 14 distances; therefore a General Vibration Assessment was performed. The General Vibration Assessment methods were used to evaluate vibration from existing freight, and future freight and passenger trains in the project corridor. Under existing conditions, freight trains travel at 10 mph on jointed track. The proposed project will result in freight trains traveling at 40 miles per hour (mph) and a passenger train moving at 60 mph, both on welded track. The General Vibration Assessment began with a data gathering task in order to construct a geographic information system (GIS) for the project. The railway alignments, surface geology, land use databases, and aerial photography were among the critical information gathered. Vibration-sensitive receptors, as listed in the FTA guidance document, were identified using land use information, internet resources, and GIS technology. Residences within the immediate vicinity of the rail line were identified in GIS. Hospitals, churches, schools, research facilities, TV studios, recording studios, concert halls, auditoriums, and theaters were identified during internet searches, and input into the GIS. Once the critical datasets had been gathered the vibration effects of existing and project-related rail usage were analyzed. In order to determine the distance to vibration impact thresholds, the generalized (reference) ground surface vibration curve was adjusted to more accurately fit the expected conditions along the new alignment. The reference curve assumes a locomotive powered passenger or freight train traveling at 50 mph on welded track, over non-efficient soil. Given the actual conditions, and current and potential future track usage, adjustments for train speed, track type, and geology were applied. The reference vibration curve adjustment factors are provided in Table 8. The surface geology of the area generally consists of a mixture of silt, sand, gravel, and floodplain sediments (all of which are assumed assumed to be non-efficient at transmitting vibration for this assessment), and till, which is assumed to be a stiff clay and efficient at transmitting vibration. The footage of till that the new (west) alignment transects was calculated and a weighted average VdB adjustment applied to the entire alignment. Other reference vibration curve adjustments were made based on the rail usage scenario, and are summarized in Table 8. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 15 Table 8 Reference Vibration Curve Adjustment Factors Reference Curve Assumptions: Vehicle Type: Locomotive Powered Passenger or Freight Speed (mph): 50 Track: Welded Geology: Normal soil, not efficient Scenario #1 (Current Use): 10 mph Freight Train Reference Adjustment Factors: Speed: -14.0 dB, calc. per FTA guidance Track (jointed): 5 dB Geology: 10 dB, for till 0 dB, for sand/gravel/sediment 0.2 dB, weighted average Total Adjustments: -8.8 dB Scenario #2 (Future Use): 40 mph Freight Train Reference Adjustment Factors: Speed: -1.9 dB, calc. per FTA guidance Track (welded): 0 dB Geology: 10 dB, for till 0 dB, for sand/gravel/sediment 0.2 dB, weighted average Total Adjustments: -1.7 dB Scenario #3 (Future Use): 60 mph Passenger Train Reference Adjustment Factors: Speed: 1.6 dB, calc. per FTA guidance Track (welded): 0 dB Geology: 10 dB, for till 0 dB, for sand/gravel/sediment 0.2 dB, weighted average Total Adjustments: 1.8 dB The new ground surface vibration curves based on the adjustment factors in Table 8, as well as the reference curve, are show in Figure 4, below. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 16 As Figure 4 shows, the 60 mph Passenger Train has the greatest potential vibration emission levels. Because of this, the vibration effects of the proposed project were assessed using vibration velocity levels generated by the 60 mph Passenger Train.. Using Figure 4, the distance to FTA ground-borne vibration impact levels were established for the various land use categories. Table 9 identifies the resulting distance to the vibration impact thresholds for each land use category. Based on the daily train counts for the current and anticipated rail there will be less than 30 vibration events (pass-bys) of the same type per day. Therefore the impact distances in Table 9 are based on Category 1, 2, and 3 land use vibration impact criteria for infrequent events. 50 55 60 65 70 75 80 85 90 95 100 10 100 1000 RMS Velocity Level (VdB) Distance from Track Centerline (ft) Figure 4 Ground Surface Vibration Curves Reference Curve (50 mph) 10 mph Freight (current) 40 mph Freight (future) 60 mph Passenger (future) Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 17 Table 9 Distances to Vibration Impact Thresholds Land Use Category Impact Level (VdB) Impact Distance (ft) 10 mph Freight Scenario (Current) 60 mph Passenger Scenario (Future) Category 1 65 158 434 Category 2 80 29 102 Category 3 83 18 74 Special Buildings 65 or 80 158 434 Results Table 10 summarizes the potential vibration impacts associated with the proposed project. Figure 5, at the end of this technical memo, contain figures showing the locations where ground-borne vibration impacts are predicted to occur. Table 10 Potential Vibration Impacts Land Use Category Number of Vibration Impacts 10 mph Freight Scenario (Current) 60 mph Passenger Scenario (Future) Category 1 0 0 Category 2 0 98 Category 3 0 2 Special Buildings 0 @65 VdB 0 @80 VdB 1 @65 VdB 0 @80 VdB As Table 10 indicates, the existing 10 mph freight train on jointed track is predicted to result in no ground-borne vibration impacts. The 60 mph passenger train on welded track would potentially add ninety-eight (98) Category 2 impacts, two (2) Category 3 impacts and one (1) Special Building impact (a TV studio). Although Category 1 land uses were identified during this assessment, none fall within the distance to calculated vibration impact threshold. Based on the limited number of train pass-by events under the Build Alternative, the potential vibration impacts at Category 2 and Category 3 land uses are considered acceptable under FTA guidance. The potential vibration impact at the television broadcast studio can be mitigated by installing track-based mitigation measures like resilient track fasteners or resilient ballast mats. Additionally, a Detailed Vibration Assessment could be performed prior to commencing corridor upgrades to identify the most appropriate track-based mitigation measure. The vibration effects associated with the Proposed Project are not considered significant. Knowledge Corridor – Restore Vermonter HDR Engineering, Inc. 18 C.6 References Federal Transit Administration, Transit Noise and Vibration Impact Assessment, May, 2006. United States Census Bureau. ―2000 U.S. Census Data.‖ Online. Available: http://factfinder.census.gov/Accessed August 2009. 291 90 91 391 91 33 20 5 5 20 116 147 20A 141 GRATTAN STREET CENTER STREET CAREW STREET RIVERDALE STREET WESTFIELD STREET EAST MAIN STREET MAIN STREET CHICOPEE STREET 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 1 116 141 141 116 391 91 91 COLLEGE STREET CABOT STREET BRIDGESTREET NEWTON STREET ROUTE 202 APPLETON STREET LINCOLN STREET PURPLE HEART DRIVE EASTHAMPTON ROAD NORTHAMPTON STREET GRANBY ROAD DWIGHT STREET LYMAN STREET BEECH STREET HAMPDEN STREET MAIN STREET INGLESIDE STREET CHICOPEE STREET MEMORIAL DRIVE CHERRY STREET 5 5 202 202 33 33 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 2 ELM STREET SOUTH STREET BRIDGE STREET CHAPEL STREET WEST STREET MOUNT TOM ROAD KING STREET PLEASANT STREET HADLEY STREET NORTH STREET HOCKANUM ROAD NORTHAMPTON STREET 5 5 91 91 47 9 66 10 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 3 5 5 91 91 1010 10 9 9 WEST STREET RUSSELL STREET NORTH KING STREET 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 4 Category 2 Severe Horn Impact 5 5 116 47 SUNDERLAND ROAD CONWAY ROAD SOUTH DEERFIELD BYPASS RIVER ROAD STATE ROAD SOUTH MAIN STREET 10 10 91 91 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 5 5 5 10 10 116 91 91 GREENFIELD ROAD CONWAY ROAD 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 6 91 91 2A 2 5 5 10 10 2 MAIN STREET BERNARDSTON ROAD FEDERAL STREET MOHAWK TRAIL FRENCH KING HIGHWAY HIGH STREET ROUTE 2 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 7 NORTHFIELD ROAD BRATTLEBORO ROAD SOUTH STREET 10 91 91 5 5 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 8 ROUTE 10 NORTHFIELD ROAD WANAMAKER ROAD HINSDALE ROAD MILLERS FALLS ROAD MOUNT HERMON STATION ROAD MAIN STREET 63 10 63 10 142 0 1,000 2,000 Feet Legend Category 3 Moderate Receptor Category 2 Severe Receptor Category 2 Moderate Receptor Wayside Noise Contour Proposed Vermonter Route Current Vermonter Route Interstate U.S. Highway State Route Sheet of 9 Wayside Noise Prepared By: Scale: 1 Inch = 2,000 Feet Knowledge Corridor -Restore Vermonter Springfield to East Northfield, Massachusetts Executive Office of Transportation 12345678 9 9 Category 2 Severe Horn Impact