Dulles Toll Road Highway Noise Wall Program 1
Purpose The purpose of the Dulles Toll Road Highway Noise Wall Program is to guide the repair or replacement of existing noise walls and assess requirements for new noise walls. 2
Need for a Noise Policy As of November 1, 2008, the Airports Authority is responsible for existing noise walls and highway noise mitigation along the Dulles Toll Road (DTR) corridor. The Dulles Toll Road Highway Traffic Noise Policy (Noise Policy) establishes assessment criteria to evaluate existing and future highway noise levels, and obligations stated in the Dulles Toll Road Transfer Agreement. To be eligible to receive federal funding on future roadway projects, the Airports Authority must have a noise policy approved by the Federal Highway Administration. 3
Chronology of Noise Policy Development of the Noise Policy began in early 2010. Public meeting held in June 2010; release of Draft Noise Policy. Noise Policy adopted by Board in February 2011. Noise Policy modified in mid 2011 to reflect comments from Federal Highway Administration and new VDOT Guidance. Revised/amended Noise Policy adopted by Board in February 2012. http://www.mwaa.com/file/dtr_noise_policy.pdf 4
Policy Fundamentals Conforms to federal and VDOT guidelines. The Airports Authority s Noise Wall Policy includes a provision to assess the eligibility of established community developments to receive mitigation for existing conditions. Under the provision, 27 Noise Sensitive Areas (NSAs) were defined as geographical areas with defined land uses eligible for noise mitigation consideration according to the Authority s Noise Policy. 5
Noise Measurement Areas Detailed maps and information are posted as PDF file, separate from this presentation. black 66
Process: Noise Policy to Noise Wall Program Development/adoption of Noise Policy. Highway noise sampling/testing. Type I analysis Noise walls that result from a highway improvement (part of future improvements). Type II analysis Re-evaluation of the existing Toll Road for potential noise mitigation. Establishment of a proposed Noise Wall Program. Community approval for reasonable new and replacement Noise Wall projects. Design and Construction. 7
Type II Noise Wall Evaluation Process for New Noise Walls Impact Do noise levels exceed maximum levels per Noise Wall Policy? Feasibility Is the noise wall effective in reducing the noise level? Can it be constructed? Reasonableness Is the noise wall cost-effective? Evaluation of Existing Noise Walls Effectiveness - Does the existing noise wall reduce the noise level effectively? Structural Integrity Is the existing noise wall structurally intact? 8
Highway Noise Sampling and Testing Example of a noise receptor used to measure sound levels Example of 24-hour noise sampling results 9
Highway Noise Model Creation Short Term noise measurements were collected concurrently with traffic counts to account for the volume and types of vehicles. These were obtained to validate the Highway Noise Model. Once the Highway Noise Model was validated, the worst case traffic scenario was applied to the model to produce the worst case noise conditions along the Dulles Toll Road Corridor. Traffic Assumptions for Highway Noise Model Rail Noise included. 4 lanes flowing at 65 mph closest to NSA on the Dulles Toll Road and 2 lanes flowing at 65 mph closest to the NSA on the Dulles International Airport Access Highway (Highest throughput of traffic). The Highway Noise Model also includes traffic on the opposite side of the Dulles Toll Road and Dulles International Airport Access Highway. Worst case noise conditions were then analyzed to begin the process of determining which properties are impacted. 10
Determination of Noise Impact Impacted areas must receive noise equal to or exceeding the following level: 66 db(a)*: Residences, places of worship, schools, hospitals, parks, and trails. 71 db(a)*: Hotels. Legend Example of Worst -Case Noise Conditions at Worldgate Condominiums * Average noise level over a one-hour period. 11
Determination of Noise Wall Feasibility Noise Wall feasibility* is established by: Overall highway traffic noise reduction of at least 5 db(a) is achievable for at least 50% of all impacted properties. Property is accessible for noise wall construction and maintenance. Non-highway noise sources, such as urban streets, do not reduce or limit the effectiveness of the proposed noise wall. *See Page 10 of the Highway Traffic Noise Policy for a complete listing of the Feasibility criteria. 12
Determination of Noise Wall Reasonableness* The maximum area of noise wall per benefited receptor shall be 1,600 square feet (sf) and the maximum allowable height of a noise barrier shall be 30 feet. Example of how reasonableness is calculated: Assume the Highway Noise Model shows 16 Benefited Receptors (BR) for a proposed noise wall that measures 1,000 feet long x 15 feet high = 15,000 sf. The square feet per Benefited Receptor = 15,000/16 BR = 937 sf/br This number is below the 1,600 maximum sf/br, therefore the Noise Wall is considered reasonable. * See page 11 of the Highway Traffic Noise Policy for a complete listing of Reasonableness criteria. 13
Recommended Noise Wall Program Noise Wall Repairs (9) Noise Wall Replacements (2) New Noise Walls (5) Current Wall Effective Outside of Current Noise Wall Parameters 14
Recommended Noise Wall Program Noise Wall Repairs (9) Reflection Lake Victoria Farms Hunter Mill Estates, Hunter Mill Overlook Sun Valley (2 Walls) Cinnamon Creek Wolf Trap Wolf Trap Woods, Carrington Tysons Village Replacement Noise Walls (2) Wolftrap Meadows Bluffs of Wolf Trap New Noise Wall Program (5) Worldgate Condominiums McLean Hamlet Odricks Corner Dulles Greene Apartments Courtyard by Marriott and Summerfield Suites 15
Noise Wall Program Results Dulles Toll Road: Western Section Noise Sensitive Areas and Recommended Noise Wall Program 16
Noise Wall Program Results Dulles Toll Road: Central Section Noise Sensitive Areas and Recommended Noise Wall Program 17
Noise Wall Program Results Dulles Toll Road: Eastern Section Noise Sensitive Areas and Recommended Noise Wall Program 18
Next Steps Complete the existing Noise Wall Repairs, 2012. Community Outreach for New and Replacement Noise Walls, beginning Fall 2012. Design and construct Wolftrap Meadows Noise Wall Replacement, 2012-2013. Design and construct New Noise Walls, 2012-2014. Planned Bluffs of Wolf Trap Noise Wall Replacement, 2014. 19
Additional Information Please contact the following MWAA Offices for information and questions related to: DTR Noise Wall Program and Construction: Engineering Office 703-417-8140 General Noise Questions: Noise Abatement Office 703-417-8745 MWAA is committed to working with every community located along the Dulles Toll Road 20
Ronald Reagan Washington National Airport Dulles Corridor Metrorail Project Dulles Toll Road Washington Dulles International Airport 21