US 53 Noise Mitigation

Transcription

1 US 53 Noise Mitigation 1

2 Meeting Agenda Introductions Brief Project Overview Terminology Agencies Involved Rules/Regulations Noise Characteristics Project Approach Mitigation Possible Noise Mitigation Details 2

3 Introductions Pat Huston, MnDOT Project Manager Rob Ege, MnDOT Design Manager John Crawford, Kimley-Horn Beth Kunkel, Kimley-Horn 3

4 Project Overview

5 Project Layout 2 nd Ave Area

6 Project Layout Midway Area

7 Noise Terminology Decibel: Sound pressure level (db) A-weighted sound level: Human perception to varying frequencies L10 - Sound level exceeded 10% of any period L50 - Sound level exceeded 50% of any period Daytime - 7:00 a.m. - 10:00 p.m. Nighttime - 10 p.m. - 7:00 a.m. 7

8 Agencies that regulate noise FHWA FTA MPCA Projects MnDOT / Local Agencies Projects MnDOT / Local Agencies 8

9 FHWA Uses Noise Impact Criteria 5 dba increase = impact Within 1 dba of criteria = impact Land Use Categories A: Serenity and quiet are of extraordinary significance B: Residences (overnight sleeping), picnic areas, etc. C: Other D: Undeveloped 9

10 FHWA Noise Abatement Criteria Noise Abatement Criteria by Land Use Category Category L10 dba Evaluation Location Land Use A 60 Exterior Special areas requiring serenity B 70 Exterior Residential C 70 Exterior Recreational D 55 Interior Churches, schools, hospitals, libraries, etc. E 75 Exterior Commercial F Agricultural and Industrial G Undeveloped 10

11 MPCA STATE NOISE STANDARDS DAYTIME NIGHTIME L10 L50 L10 L50 Residential Commercial Industrial

12 Noise Characteristics Nearly always dealing with a line source Noise levels change by 3 dba when acoustic changes by factor of 2. This applies to: Distance Traffic volume Changes of 3 dba are just barely perceptible, 5dBA is clearly noticeable 12

13 Project Approach Define Noise Monitoring Locations Conduct Noise Monitoring Model Study Area Traffic Noise to Determine Impacts Evaluate Potential Mitigation Measures Document Noise Study Findings 13

14 Noise Mitigation MnDOT cost-effectiveness criteria is used: Cost/Benefitted Receiver <= $43,500 Minimum of 7 db reduction at 1 receptor/barrier Minimum of 5 db reduction to be benefitted To be effective, noise barriers generally need to extend 4 times the distance from the barrier to the receiver, in each direction, without interruptions Mitigation materials: Standard barrier: wood plank or concrete post, earthen berms Placement of vegetation is generally not acceptable 14

15 Source-Path-Receiver Concept Source Receiver 15

16 Changes in noise levels in an outdoor environment 3 dba (increase or decrease) is barely perceptible 5 dba (increase or decrease) is clearly noticeable 10 dba (increase or decrease) is perceived as twice as loud (or half as loud) 16

17 Noise Path without a Barrier Source Receiver 17

18 Noise Path with a Barrier Barrier Source Receiver 18

19 Importance of Breaking Line of Sight Source Receiver 19

20 Importance of Breaking Line of Sight

21 Project Layout 2 nd Ave Area

22 2 ND Avenue Area Noise Mitigation Analysis Results and Cost-Effectiveness Receiver ID Build No Wall (dba) Build Wall (dba) Reduction (dba) Benefitted Receiver (>= 5dBA) Design Goal (>= 7dBA) Length (ft) Total Cost Cost per Receiver ,260 $504,000 $38, Total: 13 22

23 Noise Wall Visual Simulations 2 nd Avenue Area Images on following 2 slides: Photo of current conditions Photo simulation of proposed noise wall 23

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26 Project Layout Midway Area

27 Midway Area Noise Mitigation Analysis Results and Cost- Effectiveness Receiver ID Build No Wall (dba) Build Wall (dba) Reduction (dba) Benefitted Receiver (>= 5dBA) Design Goal (>= 7dBA) Length (ft) Total Cost Cost per Receiver ,074 $829,600 $25,

28 Midway Area Noise Mitigation Analysis Results and Cost- Effectiveness (Continued) Receiver ID Build No Wall (dba) Build Wall (dba) Reduction (dba) Benefitted Receiver (>= 5dBA) Design Goal (>= 7dBA) Length (ft) Total Cost Cost per Receiver 2,074 $829,600 $25,139 Total: 33 28

29 Noise Wall Visual Simulations Midway Area Images on following 4 slides: Photo of current conditions Photo simulation of proposed noise wall 29

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34 VOTING DEADLINE Renters and owners of benefitted properties may vote for or against the construction of the wall Official ballots are due March 20 If more than 50% of the total available points are opposed to the wall, it will not be constructed 34

35 Questions/Answers/Contacts Questions? Project contacts: Pat Huston, Project Manager, MnDOT, Rob Ege, Design Manager, MnDOT, John Crawford, Kimley-Horn, Beth Kunkel, Kimley-Horn,

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