7B, 10-96 Update on Position Paper

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Cily of Arden Hilb April 9, 2008 Page 3 of] Construction of 20' ;md 10' noise hllrricrs along the west side ofTH 10 could decrease highway noise levels by 41010 dB(A) and I 105 d13(A). respeelively_ Tbe FHWA criteria to delell11ine ifnoise barriers are feasible is that a 5 dB(A) or greater reduction in noise is achieved. As a result, considerations of noise barriers arcfeasible at the locations west ofTII 10. When noise barriers arc considered warranted and fC<Jsible, the next step in the decision-making process is to determine whether or not the barrier is l'ell,fwllab/e, or cost-effective for construction. Cost reasonableness is defined by the ratio of construction cost of the noise batTier relative to the reduction in highway noise achieved and number of benefiting residences. To be considered reasonable and remain eligible for trunk highway funding, a noise batTier can not exceed $3250 per dB(A) reduction per residence. The cost-effectiveness for the noise halTiers along the west side ofTH 10 is summarized below: RL Noise Barrier I - RL Noise Barricr 2 .- RL Noise l3an-icr 2EXT- 20'_J1<!fIi.~r $5,839/dB(A) $5)97/dB(A) $5,842/d13(/\) l<LHnrrier $10,875/dl3(/\) $9.494/dl3(A) Not Feasible Based on the Mn/DOT cost-effectiveness critcrion, the cost to construct noise barriers relative to the noise reduction achieved and the number of benefiting residcnces is not reasol1able and thercfore can not be constructed with trunk highway funding. Recommendations Based on Mn/DOT's cost panicipatioll policy, the City of Ardcn Hills has two options to consider while reviewing the findings and recommendations oCthe 'I'll 10 Noise IblTier study. First, the City can accept the findings that highway traffic noise at residences along 'Ill 10 will increase only slightly between now and 2030 without thc inSlallatioll of noise barriers. Changes in noise levels would not be noticeable by most people. Since costs are not considered reasonable relative to the reduction in noise and number of benefiting residences, the noise barriers are not eligible lor trunk highway funding. A second option the City can consider is to fund for the construction of noise barriers. The estimated construction cost for c..'lch of the noise barriers considered is summarized below: RL Noise Barrier I (870')- RL Noise Barrier 2 (2000') RL Noise Barr 2EXT (1400') --- BKD Noise Barrier (984') TOTAL 2(1.:. Barrit;;[ $26 I .000 $600,000 $420,000 i295.200 $1.576,200 lJr.!~arrier $130.500 $300,000 $210,000 $147.600 $788,100 Benefiting R~_$.i~i.GI1ces 5 11 10 _-'L_ 30 Estimated eOlls{l11ction cost is b.lscd Oil all averagc unit cost of$15 per square root and is subject to change based Oil material and labor costs.