County Road 61 (Shady Oak Road): CR 3 (Excelsior Boulevard) WELCOME. November 1, 2012

Transcription

1 : CR 3 (Excelsior Boulevard) WELCOME November 1, 2012

2 Highway Traffic Noise Facts & FAQs Why is traffic noise analyzed? In 1972, US Congress passed legislation to provide mitigation for exterior highway noise as part of all Type I Federal-Aid projects, which are those that involve one or more of the following: Construct a road on a new location, or Alteration of an existing road that significantly changes the horizontal or vertical alignment, or Increase the number of though traffic lanes for one or more miles When is there a traffic noise impact? A noise sensitive receiver (defined as homes, parks, schools, businesses, etc.) is considered impacted by noise if: Future exterior noise levels exceed the FHWA noise abatement criteria, or There is a substantial increase (5 dba) in future exterior noise levels over existing noise levels Sound Level Facts Changes in noise levels of 3 dba or less are not typically detectable by the human ear A noise level increase of 5 dba is generally readily noticeable A noise level increase of 10 dba is usually felt to be twice as loud as before Doubling of traffic = 3 dba increase in noise levels Traffic would need to triple to result in a readily perceivable (5 dba) increase in noise If a highway is moved half as close to existing homes (i.e. 200-ft to 100-ft), the noise levels will increase by 3 dba If a highway is moved double the distance from existing homes (i.e. 100-ft to 200-ft), the noise levels will decrease by 3 dba A noise barrier must be both Feasible and Reasonable to be constructed with improvement project Noise barrier is feasible if it can be constructed without major engineering or safety issues and provides a substantial noise reduction to adjacent receivers Reasonableness deals with whether or not the barrier can be constructed in a cost-effective manner, overall noise levels and noise level increases, and the desires of the adjacent residents (there is a specific formula for cost effectiveness) A noise barrier must provide a readily perceptible decrease in noise levels to adjacent receivers to be effective (5 dba at least 1 location per wall) Noise barriers reduce noise by blocking the direct travel of sound waves from a source (highway) to adjacent homes or businesses, forcing them over the top or around the barrier The barrier must be high enough and long enough to block the view (line of sight) of the highway Openings or gaps in barriers for driveway connections or streets reduce barrier effectiveness Benefit of a noise wall decreases as the listener(receiver) moves further away from the wall and is barely perceptible at distances greater than 500-ft

3 Noise Analysis for County Road Improvement Projects with Federal Funds Road Project End Study NO Are there federal funds? YES Is this a Type I Project? NO End Study YES Document & End Study NO Are noise barriers feasible? YES YES Perform Noise Analysis Do any receptors approach or exceed applicable federal noise abatement criteria? NO Document & End Study Document & End Study NO Are noise barriers reasonable? YES THIS IS WHERE WE CURRENTLY ARE AT IN THE PROCESS Do adjacent property owners want noise barrier? YES NO Document & End Study Proceed with Final Design of Noise Barriers

4 Noise Model Process Federal Highway Noise Process 1. Identify land uses along the corridor 2. Using MINNOISE, model loudest hour traffic noise levels: Existing conditions No-build: design year Build: design year 3. Compare design year noise levels to federal noise standards to determine if thresholds are reached or if there is an increase of 5 dba or more. 4. Using MINNOISE, model potential noise barriers along the corridor for receptors that exceed the federal noise standards Determine if noise barriers are feasible One receptor per barrier must receive a 5 dba reduction Maximum barrier height to be studied is 20 feet Review constructability, safety, topography, drainage, utilities, maintenance and other issues Determine if noise barriers are reasonable One receptor per barrier must meet a noise reduction of 5 dba Cost per noise barrier cannot exceed $3,250 per decibel per receptor Solicit viewpoints of benefited owners 5. Noise barriers that are feasible and reasonable will be put forward for affected residents to vote on barrier. 6. If a majority of residents vote in favor of a noise barrier that has been determined to be feasible and reasonable, it will be included as part of the project. Federal Noise Standards Land Use L10 Threshold L10 Approach Level Residential 70 dba 69 dba Commercial 75 dba 74 dba Definitions db: Decibel; a unit of sound pressure level dba: A weighted db that closely represents what humans hear L10: Sound level exceeded 10 percent of the time MINNOISE: MnDOT s computer model for developing traffic noise levels. This is the only model approved for use in Minnesota. Receptor: An outdoor place where frequent human use occurs and a lowered noise level may be of benefit. Receptors take into consideration sound that is heard at human ear height (approximately 5 feet off of the ground).

5 Environmental Analysis Items with No or Minimal Impacts Compatibility with local plans Land use compatibility Farmland Environmental Justice Air quality Threatened and endangered species Cultural resources Floodplain Potentially contaminated properties Pedestrian and bicycle accommodations

6 Environmental Analysis Items Requiring Mitigation and/or Additional Analysis Right of way and relocations - 1 commercial property relocation (Nilson Building between CSAH 61 and 21st Ave N) - 14 residential relocations 11 near TH 7 Two near 21st Avenue North One near Oak Drive Lane - Acquisition and relocation will be conducted in accordance with the Uniform Relocation Assistance and Real Property Acquisition Policies Act Noise - Existing and future noise modeled based on monitored noise levels - Walls are considered where they are both feasible and reasonable - One location on the corridor south of Mainstreet will be considered by property owners - Where walls do not meet reasonable criteria, screening may be considered - A separate meeting will be held for property owners where the wall was identified as both feasible and reasonable

7 Environmental Analysis Items Requiring Mitigation and/or Additional Analysis Wetlands: acres impacted - DNR Public Water 777P will have a modified outlet pipe - Mitigation will be at 2:1 Parks, trails and recreational areas: - Shady Oak Nature Area existing picnic tables and parking will be removed - New picnic and parking opportunities at southwest corner of the pond Stormwater runoff: - 7 treatment systems needed to address water quality Infiltration areas - Wet ponds - Hydrodynamic systems Utility relocation/reconstruction: - Exploring moving overhead utilities underground - Existing sewer and water lines will be relocated - Reconstruction of some other utilities along the corridor

8 Schedule November Open house - Environmental Assessment Worksheet comments due (November 9, 2012) November 2012 to June Federal Environmental Assessment process November 2012 December Right of way acquisition June 2013 December Final Construction Plans Completed April Construction Begins Fall Construction Completed

9 Noise Analysis Noise Analysis (1) (2) Diff. Btwn Exist & Receptor Existing No Build Build 2030 Bld Location L 10 (dba) L 10 (dba) L 10 (dba) (dba) R1 C R1A R R2 C R2A R R3 C R3A R R4 C R4A R R5 R R5A R R6 * R R6A R R7 R R7A R R8 R R8A R R9 R R10 R R10A R R11 R R11A R R12 R R12A R R13 R R14 R R15 R R15A R R16 R R17 R R18 R R19 R R20 R R21 R R22 R R22A R R23 R R23A R R24 R R24A R R25 R R25A R R26 R R26A R R27 R R27A R R28 R R28A R R29 C R30 R R30A R R31 R R31A R R32 R R32A R R33 C R33A R R34 C R34A R R35 R R36 R Noise Validation Table X: Existing Noise Levels and Model Calibration Location Classificati Date Time L 10 (dba) L 10 (dba) Monitored Modeled Difference M2 R 10/8/ :25: M3 R 10/8/ :48: M4 C 10/8/ :15: M5 R 10/8/ :38: M6 R 10/8/ :59: M7 R 10/8/ :23: M8 R 10/8/ :56: M9 R 10/8/ :12: Table Created October 18, Revised November 3, 2010 CSAH 61/Excelsior average speed = 39 mph TH 7 average speed = 55 mph All other streets = 30 mph R-Zoned Residential C-Zoned Commercial/Business/Industrial db levels Common Noise Sources Shotgun blast Jet engine 100 feet away Rock concert Car horn, snowblower Blow dryer, subway, helicopter, chainsaw Motorcycle, lawn mower, convertible ride on highway Factory, noisy restaurant, vacuum, screaming child Car, alarm clock, city traffic Conversation, dishwasher Moderate rainfall Refrigerator Whisper, library Watch ticking Federal Residential Criteria ( R ) Federal Commercial Criteria ( C ) Bold Numbers approach or exceed Federal Noise Abatement Criteria Table Created October 15, Revised November 7, Revised April 7, 2012 * - Property proposed for acquisition (1) 2030 No Build Model Includes Speeds from Simulated Traffic Analysis No Build Peak Noise Hour is: 3:00-4:00pm (2) 2030 Build Model Includes Speeds from Simulated Traffic Analysis. R-Zoned Residential C-Zoned Commercial/Business/Industrial

10 Noise Receptor Locations

11 Project History Hennepin County studies CSAH 61 CSAH 3 to TH 7 - Hopkins & Minnetonka approve a concept which includes a number of business acquisitions County obtains federal funds. Concept revised to reduce land impacts and costs - Hopkins & Minnetonka briefed on a new concept at a joint council session January August st public open house meeting on the new concept. Comments incorporated where feasible - Meetings held individually with the cities to review the new concept. Both cities agreed to move forward with the new concept but offered a few changes - Concept revised to incorporate comments - Environmental analysis and review occurs October Environmental Assessment Worksheet completed for the corridor and distributed to review agencies - Cities approve right of way agreement and Community Works redevelopment and improvement agreement

12 Similar Noise Walls