MAY 5, 2011 Noise Barrier Presentation SE Quadrant Noyes Street and Lincoln Street Jacobs Engineering Group Group Inc. Inc. 1
Introductions Agenda Overview of Interchange Project Overview of noise barrier process Fundamentals of sound & proposed noise barrier Discussion and voting 2
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Existing Methuen Rotary (Exit 46; 2004) Proposed Partial Cloverleaf at Exit 46; approx. 2016 4
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Sound Fundamentals Pressure Wave Travels in a Straight Line Threshold of Hearing 20 MicroPascals = 0 Decibels Hearing Range Spans 0 to 110 db A-Weighted Decibels 6
Sound Levels in Decibels The A-weighting Curve (dba) approximates how people hear sound 7
Sound Level (dba) Sound Study Uses the Leq Energy-Average Sound Level Time 8
Common Sound Levels Jacobs Engineering Group, Group Inc. Inc. 9
Sound Attenuation Waves spread out with distance Waves are reflected by terrain and structures Waves are absorbed and blocked by sound barrier walls 10
Highway Sounds 11
Distance Attenuation -3 dba for every doubling of distance from a roadway Travel lane sound source Inc. 3 6 9 12 Distance (feet) 12
Sound Barrier Walls An effective sound wall blocks the line of sight to most sections of a roadway 13
Acoustic Study Process Measurements Over 8 Days October 2008 Calculate Future Sound Levels Determine Traffic Noise Impacts Design Noise Mitigation 14
Noise Study Assumptions Analyze the Noisiest Traffic Hour (NTH) L eq for 2 p.m. to 3 p.m. weekday Dry roads, calm winds No leaves on trees 15
Sound Fundamentals Change in Sound Levels 3 dba Just Audible 5 dba Noticeable 10 dba Double Loudness 16
Study Area & Sound Monitoring Locations 27 Smith Ave. Valley Office Park 1 Heather Dr. 447 Lowell St. 16 Allen St. 4 Noyes St. 17
Acoustic Study FHWA Traffic Noise Model (TNM) Study Alternatives 2009 Existing Conditions 2030 No-Build 2030 Build Improvements Sound levels predicted at homes within 500 feet of project roadways 18
Sound Levels At Homes Within 500 of I-93, Routes 110/113 Study Condition 1-hour L eq (dba) 2009 Existing Conditions 59 74 2030 No-Build 61 75 2030 Build Improvements 62 75 19
Typical Noise Barrier 20
MassDOT Noise Abatement Policy Type I Noise barriers built as part of new highway construction Type II Noise barriers built on existing highways (no new highway construction) 21
MassDOT and FHWA Define a Traffic Noise Impact as a Sound Level at a Residence 66 + dba, or Increase of 10 dba 22
MassDOT Noise Abatement Policy Feasibility of Noise Barrier Goal Noise barrier to achieve a 10 dba reduction for first row of residences Minimum Requirement - Achieve a 7 dba reduction for first row of residences Issues to consider Include: Driveways Cross Streets Wetlands 23
MassDOT Noise Abatement Policy Reasonableness of Noise Barrier Cost Effectiveness Index (CEI) <= $2,700 CEI = Barrier cost $ 1 / # homes protected / insertion loss in dba Example CEI = $2,696 = $496,000 / 23 Homes protected / 8.0 dba 1 Using an assumed cost of $16/SF. Actual costs are higher at $65/SF. 24
Noyes Street/Lincoln Street Noise Barrier Design Average Noise Reduction 35 Homes 8.9 dba Noise Barrier Dimensions Length 1,875 feet Height 24 feet above grade for center section, 18 feet in front of Lincoln Street, tapering to 12 feet east of Lincoln Street Height 12 feet on bridge deck over Riverside Dr. 25
Noyes Street/Lincoln Street Noise Barrier Design Shorter Alternative Average Noise Reduction 25 Homes 8.4 dba No protection for Lincoln St. Homes Noise Barrier Dimensions Length 1,450 feet Height 24 feet above grade, ends west of Lincoln St. Height 12 feet on bridge deck over Riverside Dr. 26
Noyes Street / Lincoln Street Existing Sound Levels (2009) 65 to 74 dba Future Sound Levels No Barrier (2030) 65 to 74 dba Future Sound Levels with Barrier (2030) 58 to 66 dba 27
Sound Levels in 2030 Residence No Barrier With Barrier Reduction (dba) (dba) (dba) 1068 Riverside Drive 70.7 69.2 1.5 1070 Riverside Drive 68.9 67.6 1.3 1073 Riverside Drive 72.6 66.2 6.4 4 Noyes Street 69.8 59.8 10.0 5 Noyes Street 72.8 60.8 12.0 7 Noyes Street 73.5 61.2 12.3 8 Noyes Street 70.1 60.6 9.5 9 Noyes Street 73.8 61.5 12.3 10 Noyes Street 70.9 61.7 9.2 11 Noyes Street 74.1 62.1 12.0 12 Noyes Street 71.2 61.7 9.5 13 Noyes Street 73.9 61.9 12.0 15 Noyes Street 73.6 61.6 12.0 16 Noyes Street 70.8 61.0 9.8 17 Noyes Street 72 61.5 10.5 18 Noyes Street 70.6 61.0 9.6 19 Noyes Street 71.8 61.9 9.9 20 Noyes Street 70.6 61.3 9.3 21 Noyes Street 70.7 62.2 8.5 28
Sound Levels in 2030 Residence No Barrier With Barrier Reduction (dba) (dba) (dba) 22 Noyes Street 70.5 61.3 9.2 24 Noyes Street 69.8 61.1 8.7 25 Noyes Street 70.7 63.3 7.4 26 Noyes Street 69.6 61.8 7.8 27 Noyes Street 71.5 65.7 5.8 28 Noyes Street 69.5 62.8 6.7 30 Noyes Street 69.4 63.3 6.1 34 Noyes Street 69.3 65.0 4.3 Aster Street 68.4 59.5 8.9 10 Lincoln Street 67.2 59.4 7.8 11 Lincoln Street 67.6 58.5 9.1 12 Lincoln Street 66.3 58.9 7.4 14 Lincoln Street 65.8 58.7 7.1 15 Lincoln Street 67 58.6 8.4 16 Lincoln Street 65.2 58.5 6.7 17 Lincoln Street 66.4 58.4 8.0 18 Lincoln Street 65.1 58.4 6.7 19 Lincoln Street 66.5 58.7 7.8 27 Lincoln Street 66.5 59.1 7.4 29
Methuen Noise Barrier Context 30
Barrier Noyes and Lincoln streets 4 3 2 Proposed Noise Barrier 1 31
Existing View #1 25 Noyes Street 32
Barrier Appearance #1 25 Noyes Street Preliminary Artist s Rendering 33
Barrier Appearance #1 25 Noyes Street Preliminary Artist s Rendering Existing View Proposed noise barrier as seen from Noyes Street 34
Existing View #2 13 and 15 Noyes Street 35
Barrier Appearance #2 13 and 15 Noyes Street Preliminary Artist s Rendering 36
Barrier Appearance #2 View From Noyes Street Homes Existing View Proposed noise barrier as seen from Noyes Street 37
Existing View #3 From Noyes Street 38
Barrier Appearance #3 From Noyes Street 39
Barrier Appearance #3 View From Noyes Street Preliminary Artist s Rendering Existing View Proposed noise barrier as seen from Noyes Street 40
Existing View #4 From Lincoln Street 41
Barrier Appearance #4 From Lincoln Street Preliminary Artist s Rendering 42
Barrier Appearance #4 View From Lincoln Street Preliminary Artist s Rendering Existing View Proposed noise barrier as seen from Lincoln Street 43
Noise Barrier Design Schedule First Abutter Meeting today! Second Abutter Meeting to discuss noise barrier design and landscaping Fall 2011 44
Questions/Voting 45