Traffic Noise Analysis
I-55 Phase I Engineering Study
Veterans Memorial Tollway (I-355) to Dan Ryan Expressway (I-90/94)
Prepared for:
July 2016
I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
TABLE OF CONTENTS
Page 1. INTRODUCTION............................................................................................................................................ 1 2. NOISE BACKGROUND AND REGULATIONS ............................................................................................ 1
Noise Background ........................................................................................................................ 1 Federal Regulations ...................................................................................................................... 2 IDOT Policy ..................................................................................................................................... 3
3. NOISE RECEPTOR SELECTION .................................................................................................................... 3 4. NOISE MONITORING ................................................................................................................................... 7
Traffic Volumes .............................................................................................................................. 8 Time of Day for Measurements .................................................................................................. 8 Weather Conditions ..................................................................................................................... 8 Instrumentation ............................................................................................................................. 8 Field Noise Monitoring Results and Model Validation ........................................................... 8
5. NOISE ANALYSIS METHODOLOGY ............................................................................................................ 9 Traffic Volumes ............................................................................................................................ 10 Traffic Composition and Speed Conditions .......................................................................... 10 Receptor Distance/Elevation ................................................................................................... 10
6. TNM RESULTS AND TRAFFIC NOISE IMPACTS ......................................................................................... 10 Observations and Conclusions ................................................................................................ 13
7. ABATEMENT ANALYSIS .............................................................................................................................. 14 Abatement Alternatives ............................................................................................................ 14 Feasibility and Reasonableness ............................................................................................... 15 Noise Barrier Analysis .................................................................................................................. 16 Cost Averaging ........................................................................................................................... 19
8. PERMITTING OF PLANNED DEVELOPMENTS .......................................................................................... 20 9. COORDINATION WITH LOCAL OFFICIALS FOR UNDEVELOPED LANDS ........................................... 20 10. CONSTRUCTION NOISE ............................................................................................................................ 21 11. VIEW POINT SOLICITATION....................................................................................................................... 22
Agency Coordination ................................................................................................................ 22 Noise Forums ................................................................................................................................ 22 Viewpoint Solicitation ................................................................................................................ 22
12. CONCLUSION ............................................................................................................................................ 23
LIST OF TABLES TABLES 1. FHWA NOISE ABATEMENT CRITERIA – HOURLY WEIGHTED SOUND LEVEL ......................................... 3 2. REPRESENTATIVE RECEPTORS .................................................................................................................... 5 3. NOISE MONITORING RESULTS, Leq ........................................................................................................... 9 4. NOISE LEVELS SUMMARY – TNM MODELING RESULTS ......................................................................... 10 5. PERCEPTABLE NOISE CHANGES FROM NO BUILD TO BUILD CONDITIONS ...................................... 14 6. ADJUSTED ALLOWABLE COST PER BENEFITED RECEPTOR .................................................................. 17 7. NOISE ABATEMENT ANALYSIS SUMMARY .............................................................................................. 18 8. COST AVERAGING ANALYSIS SUMMARY .............................................................................................. 19 9. VIEWPOINT SOLICITATION SUMMARY ................................................................................................... 22
APPENDIX A: LIST OF FIGURES
FIGURES 1 PROJECT LOCATION MAP 2 LAND USE MAP 3 NOISE RECEPTORS AND BARRIERS
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
APPENDIX B: COORDINATION WITH LOCAL OFFICIALS
Letter – Village of Burr Ridge Letter – City of Chicago Letter – City of Darien Letter – County of DuPage Letter – Village of Hodgkins Letter – Village of Indian Head Park Letter – Village of Willowbrook
APPENDIX C: VIEWPOINT SOLICITATIONS
Minutes – City of Chicago, 11th Ward Minutes – Village of Burr Ridge Minutes – Village of Countryside Minutes – City of Darien Minutes – DuPage County Minutes – DuPage County Forest Preserve Minutes – Village of Hodgkins Minutes – Village of Indian Head Park Minutes – Village of Summit Minutes – Village of Woodridge Noise Forum Summary Viewpoint Solicitation Letter Viewpoint Solicitation Ballots Viewpoint Solicitation Comments
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
SECTION 1: INTRODUCTION Interstate 55 (I-55), commonly referred to as the Stevenson Expressway in Cook County, provides the primary southwest-northeast roadway access to the Chicago central business district. It serves Cook County, DuPage County and Will County in the Chicago Metropolitan area. The project limits, shown in Figure 1, connect the Veterans Memorial Tollway (I-355, the metropolitan area’s outer regional circumferential route) at the southern terminus, the Tri-State Tollway (I-294, the metropolitan area’s inner circumferential route) and I-90/94 (Dan Ryan Expressway) to the north. Fiscal constraints and adjacent community impacts eliminated the consideration of reconstructing the existing facility. As such, one additional lane (in each direction of I-55 travel) is being proposed within the existing median. The existing general purpose lanes are in good condition and will not be reconstructed or rehabilitated as part of the improvement. Furthermore, no interchanges or crossing roadways will be reconstructed or improved as part of this project and no change in roadway elevation is proposed. The new managed lane will utilize congestion pricing strategies to maintain reliable service, even during congested morning and evening peak hours. This traffic noise analysis has been prepared to evaluate traffic noise for the I-55 Managed Lane Study. The noise study area is within the communities of Woodridge, Darien, Lemont, Willowbrook, Burr Ridge, Indian Head Park, Countryside, McCook, Hodgkins, Summit, Forestview, Stickney and Chicago. The noise study evaluates existing and anticipated future traffic noise conditions, and will evaluate potential noise abatement measures if appropriate. SECTION 2: NOISE BACKGROUND AND REGULATIONS Noise Background Sound is a pressure fluctuation in air, transmitting mechanical energy caused by vibration. Noise is unwanted sound. Loudness is measured on a logarithmic scale using units of decibels (dB). Sound is composed of a wide range of frequencies; however, the human ear is not uniformly sensitive to all frequencies. Therefore, an "A" weighted scale was devised to correspond with the sensitivity of the human ear. The A-weighting generally weights more heavily noise levels in the humanly audible range and screens out noise levels that cannot be heard but are still generated, such as by a high-frequency dog whistle. The A-weighted scale is used because:
1) It is easily measured. 2) It approximates the sensitivity of the human ear to sounds of different frequencies. 3) It matches attitudinal surveys of noise annoyance better than other noise measurements. 4) It has been adopted as the basic unit of environmental noise by many agencies around
the world for community noise issues. The equivalent sound level (Leq) is the steady-state, A-weighted sound level that contains the same amount of acoustic energy as the actual time-varying, A-weighted sound level over a specified period. If the period is 1 hour, the descriptor is the hourly equivalent sound level or Leq(h), which is widely used by state highway agencies as a descriptor of traffic noise. It is generally the equivalent level of sound (in dB(A)) that represents the level of sound, held constant over a specified period, that denotes the same amount of energy as the actual fluctuating noise over that period. Leq is based on the energy average, not a noise level average.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Federal Regulations
Traffic noise analyses are required for all projects considered a Type I project. Federal regulations define Type I projects as any of the following:
• The construction of a highway on new location, • The physical alteration of an existing highway where there is either:
o Substantial Horizontal Alteration. A project that halves the distance between the traffic noise source and the closest receptor between the existing condition to the future build condition, or
o Substantial Vertical Alteration. A project that removes shielding therefore, exposing the line-of-sight between the receptor and the traffic noise source (This is done by either altering the vertical alignment of the highway or by altering the topography between the highway traffic noise source and the receptor),
• The addition of a through-traffic lane(s). (This includes the addition of a through-traffic lane that functions as a HOV lane, High-Occupancy Toll [HOT] lane, bus lane, or truck climbing lane),
• The addition of an auxiliary lane, except for when the auxiliary lane is a turn lane, • The addition or relocation of interchange lanes or ramps added to a quadrant to
complete an existing partial interchange, • Restriping existing pavement for the purpose of adding a through-traffic lane or an auxiliary
lane, or, • The addition of a new or substantial alteration of a weigh station, rest stop, rideshare lot or
toll plaza. This proposed improvement to I-55 meets the characteristics of a Type I noise project as it proposes the addition of through-traffic lanes within the existing median of the roadway. Federal regulations establish noise abatement criteria to establish noise levels where noise abatement should be evaluated. Five separate noise abatement criteria (NAC) based upon land use are used by the FHWA to assess potential noise impacts. A traffic noise impact occurs when noise levels approach (within 1 dB(A)) or exceed the NAC listed in Table 1.1 In determining the applicable noise activity category for the study area, existing land use was reviewed. The applicable NAC for all residential noise receptors evaluated is 67 dB(A).
1 Based on 23 Code of Federal Regulations Part 772, Procedures for Abatement of Highway Traffic Noise and Construction Noise (adopted 2010).
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
TABLE 1 FHWA NOISE ABATEMENT CRITERIA - HOURLY WEIGHTED SOUND LEVEL
Activity Category2
Activity Criteria dB(A) Leq(h) Description of Activity Category
A 57 (Exterior)
Lands on which serenity and quiet are of extraordinary significance and serve an important public need and where the preservation of those qualities is essential if the area is to continue its intended purpose
B* 67 (Exterior) Residential
C* 67 (Exterior)
Active sport areas, amphitheaters, auditoriums, campgrounds, cemeteries, day care centers, hospitals, libraries, medical facilities, parks, picnic areas, places of worship, playgrounds, public meeting rooms, public or nonprofit institutional structures, radio studios, recording studios, recreation areas, Section 4(f) sites, schools, television studios, trails, and trail crossings
D 52 (Interior)
Auditoriums, day care centers, hospitals, libraries, medical facilities, places of worship, public meeting rooms, public or nonprofit institutional structures, radio studios, recording studios, schools, and television studios
E* 72 (Exterior)
Hotels, motels, offices, restaurants/bars, and other developed lands, properties or activities not included in A-D or F
F -------------- Agriculture, airports, bus yards, emergency services, industrial, logging, maintenance facilities, manufacturing, mining, rail yards, retail facilities, shipyards, utilities (water resources, water treatment, electrical), and warehousing
G -------------- Undeveloped lands that are not permitted
*Includes undeveloped lands permitted for this activity category
IDOT Policy
Based on the FHWA regulations, State Highway Authorities are allowed to define the noise impacts as 1) the build noise level determined to approach the NAC and 2) the increase in build noise levels determined to be a substantial increase from existing levels. The Illinois Department of Transportation (IDOT) defines noise impacts as follows:
• Design-year traffic noise levels approach, meet or exceed the NAC, with approach defined as 66 dB(A) for the residential NAC of 67 dB(A).
• Design-year traffic noise levels are a substantial increase over existing traffic-generated noise levels, defined as an increase greater than 14 dB(A).
SECTION 3: NOISE RECEPTOR SELECTION A traffic noise receptor is a discrete or representative location within a Common Noise Environment (CNE); a CNE is a group of receptors with the same Activity Category designation (as detailed in Table 1, above) and which share similar topographical characteristics and a similar level of exposure to noise sources. A “representative” receptor is a location within a CNE that represents the worst-case noise level (often determined by proximity to the dominant noise source, which for this analysis is the I-55 facility) for all other individual represented receptors within that CNE. Traffic noise impacts are defined only for the Build condition, per IDOT policy, and include all representative receptors that would have noise levels that approach (fall within 1 dBA), meet, or exceed the NAC presented in Table 5 above. Receptor locations are selected to reflect changes in traffic noise levels as a result of changes in traffic volumes, speed, composition (trucks and cars), roadway alignment (horizontal and vertical), number of lanes, shielding, and ground cover. Proximity to I-55 was the primary factor used to select receptors for modeling and analysis, and was limited to receptors within 500 feet of the proposed outside edge of pavement. The distance of 500 feet is based on FHWA’s 2010 performance evaluation of the Traffic Noise Model (TNM) 2.5, the model used to predict existing,
2 FHWA does not determine interior noise impacts for residential land uses. An interior noise analysis is completed only if no exterior areas of frequent human use exist.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
no build, and build noise levels for this analysis. The evaluation found that TNM is most accurate when used to assess receptors within 500 feet of the roadway, and that TNM under-predicted sound levels for “soft” ground types (turf) and over-predicted sound levels for “hard” ground types (pavement) for receptors farther than 500 feet from the roadway.3 The IDOT Highway Traffic Noise Assessment Manual (2011) states that noise receptors should be screened within 500 feet of the roadway, based upon the findings of the FHWA 2010 performance evaluation. Table 2 lists the, location, type, and the approximate distance to the existing I-55 edge of pavement for each of the representative receptors selected for this analysis. Figure 3 depicts aerial photographs of each representative receptor and its corresponding CNE. Land uses identified within the project limit of study (approximately 500 feet from proposed edge of pavement) include residences (Activity Category B); active sport areas, playgrounds/recreation areas, cemeteries, daycare centers, hospitals/medical facilities, parks, schools, and trails (Activity Category C); hotels, offices, and restaurants (Activity Category E); agricultural lands, bus yards, emergency services, industrial uses, maintenance facilities, manufacturing, rail yards, retail facilities, utilities, and warehousing (Activity Category F); and undeveloped lands (Activity Category G). Activity Categories B and C have a Noise Abatement Criteria (NAC) level of 67 dBA. Activity Category E has an NAC of 72 dBA, and Activity Categories F and G have no NAC level. The activity categories for the land uses identified within approximately 500 feet of roadway edge of pavement in the project area are presented in Figure 2. IDOT policy stipulates that when determining traffic noise impacts, primary consideration shall be given to exterior areas within Activity Category A, B, C and E land uses where frequent human use occurs. Examples include (but are not limited to) the following:
• Residences: back yards, front yards, decks, and/or patios • Schools: playgrounds • Nursing Homes: decks and/or patios • Parks: pavilion areas, picnic tables • Cemeteries: points of anticipated gathering (i.e., bench, pavilion or shelter) • Trails / Trailheads: points of anticipated gathering (i.e., bench, information boards)
Potential traffic noise impacts for receptors within Activity Category D land uses are investigated for interior areas, but only if the building(s) are located within 500 feet of the proposed edge of pavement and if the location has no outdoor areas of frequent human use (i.e., no outdoor noise receptors). Since outdoor areas of frequent human use (Activity Category C) were identified at each potential Activity Category D land use, no interior analysis was conducted for this study. In some cases, an identified CNE contains Activity Category E land uses which have no apparent areas of frequent outdoor use; in such cases, no representative receptor has been selected. One hundred and sixteen (116) receptors have been selected to represent noise-sensitive land uses in the project area. Each receptor represents a CNE. Table 2, below, lists each representative receptor, a description of the land use represented, its activity category and associated NAC, the approximate distance to the nearest major roadway edge of pavement, and its community of location. Representative receptors and their respective CNEs are shown on Figure 3.
3 U.S. Department of Transportation Research and Innovative Technology Administration. “Ground and Pavement Effects using FHWA’s Traffic Noise Model 2.5.” April 2010.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
TABLE 2 REPRESENTATIVE RECEPTORS
INTERSTATE I-55: I-355 (VETERANS MEMORIAL TOLLWAY) TO I-90/94 (DAN RYAN EXPRESSWAY)
Receptor Land Use Description Activity
Category (NAC dB[A])
Distance (Feet) to I-55 Existing Edge
of Pavement Geographic Area
R1 Single-Family Residence B (67) 320 Woodridge
R2 Permitted Residential Development B (67) 235 Woodridge
R3 Single-Family Residence B (67) 135 Lemont
R4 Office E (67) 465 Darien
R5 Active Sport Area (Equestrian) C (67) 260 Darien
R6 Single-Family Residence B (67) 110 Darien
R7 Multi-Family Residence B (67) 155 Darien
R8 Active Sport Area (Golf Course) C (67) 165 Darien
R9 Multi-Family Residence B (67) 130 Darien
R10 Single-Family Residence B (67) 270 Darien
R11 Active Sport Area (Golf Course) C (67) 360 Darien
R12 Single-Family Residence B (67) 90 Darien
R13 Single-Family Residence B (67) 175 Darien
R14 Church Playground C (67) 80 Darien
R15 Multi-Family Residence B (67) 460 Darien
R16 Single-Family Residence B (67) 290 Darien
R17 Office E (72) 175 Darien
R18 Hotel E (72) 250 Woodridge
R19 Playground C (67) 205 Darien
R20 Multi-Family Residence B (67) 145 Darien
R21 Single-Family Residence B (67) 140 Darien
R22 Single-Family Residence B (67) 160 Darien
R23 Restaurant E (72) 490 Darien
R24 Single-Family Residence B (67) 355 Darien
R25 Single-Family Residence B (67) 193 Darien
R26 Single-Family Residence B (67) 215 Darien
R27 Multi-Family Residence B (67) 125 Darien
R28 Multi-Family Residence B (67) 165 Willowbrook
R29 Single-Family Residence B (67) 130 Willowbrook
R30 Multi-Family Residence B (67) 140 Willowbrook
R31 Playground C (67) 235 Willowbrook
R32 Single-Family Residence B (67) 143 Willowbrook
R33 Single-Family Residence B (67) 115 Darien
R34 Single-Family Residence B (67) 130 Willowbrook
R35 Single-Family Residence B (67) 161 Willowbrook
R36 Single-Family Residence B (67) 420 Burr Ridge
R37 Hotel E (72) 295 Willowbrook
R38 Single-Family Residence B (67) 180 Willowbrook
R39 Restaurant E (72) 350 Willowbrook
R40 Restaurant E (72) 250 Willowbrook
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Receptor Land Use Description Activity
Category (NAC dB[A])
Distance (Feet) to I-55 Existing Edge
of Pavement Geographic Area
R41 Restaurant E (72) 190 Burr Ridge
R42 Office E (72) 120 Burr Ridge
R43 Single-Family Residence B (67) 240 Burr Ridge
R44 Park/Active Sports Area C (67) 350 Burr Ridge
R45 Single-Family Residence B (67) 415 Burr Ridge
R46 Office/Conference Center E (72) 156 Burr Ridge
R47 Single-Family Residence B (67) 415 Burr Ridge
R48 Hotel E (72) 530 Burr Ridge
R49 Office E (72) 220 Burr Ridge
R50 Single-Family Residence B (67) 195 Indian Head Park
R51 Single-Family Residence B (67) 170 Burr Ridge
R52 Single-Family Residence B (67) 125 Burr Ridge
R53 Multi-Family Residence B (67) 305 Indian Head Park
R54 Single-Family Residence B (67) 180 Countryside
R55 Park C (67) 200 Countryside
R56 Office E (72) 345 Countryside
R57 Single-Family Residence B (67) 95 Countryside
R58 Single-Family Residence B (67) 80 Countryside
R59 Single-Family Residence B (67) 80 Countryside
R60 Restaurant/Bar E (72) 457 Countryside
R61 Playground C (67) 210 Countryside
R62 Single-Family Residence B (67) 120 Countryside
R63 Single-Family Residence B (67) 190 Countryside
R64 Single-Family Residence B (67) 195 Hodgkins
R65 Single-Family Residence B (67) 345 Hodgkins
R66 Park C (67) 415 Summit
R67 Single-Family Residence B (67) 225 Summit
R68 Park C (67) 195 Chicago
R69 Single-Family Residence B (67) 310 Chicago
R70 Single-Family Residence B (67) 445 Chicago
R71 Park C (67) 230 Chicago
R72 Playground B (67) 210 Chicago
R73 Park C (67) 440 Chicago
R74 Single-Family Residence B (67) 440 Chicago
R75 Multi-Family Residence B (67) 120 Chicago
R76 Single-Family Residence B (67) 375 Chicago
R77 Mixed-Use Residential B (67) 225 Chicago
R78 Park (Playground) C (67) 490 Chicago
R79 Multi-Family Residence B (67) 240 Chicago
R80 Single-Family Residence B (67) 235 Chicago
R81 Single-Family Residence B (67) 185 Chicago
R82 Single-Family Residence B (67) 170 Chicago
R83 Single-Family Residence B (67) 175 Chicago
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Receptor Land Use Description Activity
Category (NAC dB[A])
Distance (Feet) to I-55 Existing Edge
of Pavement Geographic Area
R84 Single-Family Residence B (67) 205 Chicago
R85 Single-Family Residence B (67) 165 Chicago
R86 Single-Family Residence B (67) 215 Chicago
R87 Single-Family Residence B (67) 230 Chicago
R88 Single-Family Residence B (67) 205 Chicago
R89 Single-Family Residence B (67) 260 Chicago
R90 Single-Family Residence B (67) 260 Chicago
R91 Single-Family Residence B (67) 291 Chicago
R92 Multi-Family Residence B (67) 190 Chicago
R93 Mixed- Use Residential B (67) 50 Chicago
R94 Multi-Family Residence B (67) 315 Chicago
R95 Multi-Family Residence (Balcony) B (67) 50 Chicago
R96 Multi-Family Residence B (67) 60 Chicago
R97 Single-Family Residence B (67) 60 Chicago
R98 Multi-Family Residence (Balcony) B (67) 225 Chicago
R99 Single-Family Residence B (67) 185 Chicago
R100 Mixed-Use Residential B (67) 220 Chicago
R101 Single-Family Residence B (67) 340 Chicago
R102 Single-Family Residence B (67) 355 Chicago
R103 Mixed-Use Residential B (67) 220 Chicago
R104 Mixed-Use Residential B (67) 230 Chicago
R105 Single-Family Residence B (67) 385 Chicago
R106 Single-Family Residence B (67) 305 Chicago
R107 Single-Family Residence B (67) 265 Chicago
R108 Multi-Family Residence (Rooftop Balcony) B (67) 150 Chicago
R109 Single-Family Residence B (67) 450 Chicago
R110 Single-Family Residence B (67) 215 Chicago
R111 Park C (67) 485 Chicago
R112 Multi-Family Residence B (67) 245 Chicago
R113 Multi-Family Residence B (67) 140 Chicago
R114 Single-Family Residence B (67) 290 Chicago
R115 Mixed-Use Residential B (67) 355 Chicago
R116 Single-Family Residence B (67) 490 Chicago
SECTION 4: NOISE MONITORING Noise level monitoring provides a “snapshot” of existing site conditions. Field measurements and the data collected during monitoring are used to validate TNM to ensure it accurately predicts each area’s noise environment. Traffic noise levels measured during monitoring events are representative of the traffic characteristics (volume, speed, and composition) for the period measured. The period measured may or may not be the peak-hour traffic condition. The monitored noise levels may be influenced by noise sources in the area other than traffic noise or the characteristics of the location that are represented in the traffic model, such as shielding afforded by existing berms or structures.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Noise monitoring in the I-55 project corridor was conducted at 25 receptor locations, representing noise-sensitive land uses and noise environments present in the corridor. The selection of these locations was reviewed and approved by IDOT and FHWA. Traffic Volumes
Traffic volumes on roadways adjacent to receptors were counted during each ten-minute noise monitoring period. The number of cars and trucks were recorded separately along with any other noise sources observed during monitoring. The traffic volumes counted were extrapolated to hourly volumes for TNM input. This procedure is accepted by FHWA as a representative noise monitoring method, detailed in the IDOT Highway Traffic Noise Assessment Manual, Section 3.5.2. Time of Day for Measurements
Noise monitoring is typically conducted during the period representing the worst hourly noise level. This may or may not be during the peak hour traffic volumes, as traffic may be operating under stop-and-go conditions or at a reduced travel speed during the peak hour. Monitoring typically occurred during the midday off peak period of travel, when free-flow conditions were present on I-55, which generates higher sound levels as compared to congested peak hour conditions. Noise monitoring was conducted at the sites on November 10 and 11 and December 3, 9, and 10 of 2015. Weather Conditions
Weather conditions affect noise measurement readings. Noise measurements cannot be taken if wind speed exceeds 12 miles per hour (mph). A wind screen was used at all times during noise monitoring to reduce wind noise. The weather conditions during the noise monitoring were within the recommended ranges for all parameters, and are summarized as follows:
WEATHER CONDITIONS DURING I-55 TRAFFIC NOISE MONITORING
Date Pavement Humidity Temperature Wind Speed
Required Condition Dry Less than 90% 14 to 112 degrees F 12 mph or less
11/10/15 Dry 36%-38% 54-55 degrees F 3-8 mph
11/11/15 Dry 52%-76% 40-63 degrees F Calm-10 mph
12/3/15 Dry 73%-79% 35-37 degrees F 8-10 mph
12/9/15 Dry 79%-82% 43-47 degrees F 6-10 mph
12/10/15 Dry 58%-78% 46-53 degrees F 5-10 mph Source: National Weather Service Instrumentation
Measurements were performed using a Larson Davis Model 820 sound level meter, a Larson Davis Model CAL200 calibrator, and a Larson Davis Model PRM828 preamp with a PCB Piezotronics Model 377B02 free-field microphone. The meter calibrated prior to use was placed approximately five (5) feet from the ground in an outdoor location where human activity typically occurs. Monitoring was conducted using the A-weighted scale. Field Noise Monitoring Results and Model Validation
To validate the noise model, the noise monitoring results are compared to modeled results performed using traffic volumes and mix observed during each monitoring event (Table 3). Modeled noise levels must be within 3 dB of the monitored noise levels for the model to be validated.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Traffic noise monitoring occurred at 25 representative receptors in the study area. Monitored noise levels ranged from 60 dB(A) to 80 dB(A). The difference between modeled and monitored noise levels provides an indication of noise model validity; for this analysis, modeled noise levels are within 3 dB of the monitored levels, which, per the IDOT traffic noise policy, validates the TNM 2.5 modeling.
TABLE 3 NOISE MONITORING RESULTS (Leq)
Receptor Monitored dB(A) Modeled dB(A)* Difference
R1 71 68 -3
R6 80 77 -3
R8 71 72 1
R14 77 77 0
R19 68 68 0
R21 77 76 -1
R27 79 76 -3
R30 75 72 -3
R34 72 73 1
R38 73 72 -1
R43 71 72 1
R45 63 66 3
R61 63 65 2
R63 68 70 2
R65 71 69 -3
R66 66 66 0
R68 67 66 -1
R71 68 66 -2
R72 60 59 -1
R73 64 65 1
R80 70 70 0
R86 69 69 0
R89 65 63 -2
R97 66 63 -3
R98 70 67 -3 * Represents modeled noise levels using the existing condition traffic noise model and the traffic conditions observed
in the field during the given monitoring event. Observed traffic during noise monitoring varies from the existing predicted peak-hour traffic volumes used for project development. The modeled noise levels shown in Table 3 will vary from those in Table 4 for this reason.
SECTION 5: NOISE ANALYSIS METHODOLOGY The Preferred Alternative for the I-55 Managed Lane Study is an Express Toll Lane (ETL) with either a continuous access operation or a controlled access operation. For the purpose of this analysis, traffic volumes for the continuous access operation were utilized. This is considered a conservative approach to the evaluation as the continuous access will tend to result in slightly higher traffic volumes.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Prediction of noise levels is one step in assessing potential noise impacts and abatement strategies. Traffic noise levels were predicted using existing and future (2040) traffic volumes. Inputs into TNM are described in the following sections, and include traffic volume, traffic mix (cars, heavy trucks, and medium trucks), traffic controls, receptor distance, elevation, and average speeds during free flowing conditions. Traffic Volumes
Study area traffic volumes (daily and peak hour) utilized project traffic for the most recent year available (considered to be the existing condition), the No Build (2040) condition, and the proposed Build (2040) condition. Traffic Composition and Speed Conditions
TNM traffic volume and composition input for the project area included passenger vehicles, single-unit (medium) trucks, and multi-unit (heavy) trucks. Traffic mix observed during the noise level monitoring conducted for the project indicate that heavy truck volumes ranged from 77% to 92% of total truck traffic throughout the corridor. For all conditions, the percentage of truck traffic for the I-55 mainline is estimated to be between 8% and 13%, with automobiles (passenger vehicles) accounting for the balance of the total traffic composition. As free-flow conditions were assumed for the modeling of existing and future-condition noise levels, the posted speed limit (55 mph) was used for I-55 in TNM modeling. Receptor Distance/Elevation
The distance and elevation of each receptor influences the predicted traffic noise level. As shown in Table 2, distances from representative receptors to I-55 edge of pavement range from 50 feet (Receptors R93 and R95) to 530 feet (Receptor R48). The specific location of the receptor is based upon the location where outdoor activity occurs, verified via aerial photography and field reviews. SECTION 6: TNM RESULTS AND TRAFFIC NOISE IMPACTS Existing, No Build (2040), and Build-condition (2040) traffic noise levels were predicted for 116 representative receptors utilizing TNM 2.5. Receptor locations are illustrated on Figure 3 (Appendix A). Table 4 presents the modeled noise levels, as well as the anticipated difference in noise levels for these scenarios:
TABLE 4 NOISE LEVELS SUMMARY – TNM MODELING RESULTS
Receptor Number
Activity Category
(NAC dB[A])
Existing dB(A)
No Build (2040) dB(A)
Difference (Existing to No Build)
Build (2040) dB(A)
Difference (No Build to Build) Community
R1 B (67) 66 68 2 67 -1 Woodridge
R2 B (67) 66 68 2 68 0 Woodridge
R3 B (67) 59 61 2 61 0 Lemont
R4 E (72) 63 64 1 66 2 Darien
R5 C (67) 65 67 2 68 1 Darien
R6 B (67) 73 75 2 76 1 Darien
R7 B (67) 70 72 2 73 1 Darien
R8 C (67) 70 72 2 73 1 Darien
R9 B (67) 72 73 1 74 1 Darien
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Receptor Number
Activity Category
(NAC dB[A])
Existing dB(A)
No Build (2040) dB(A)
Difference (Existing to No Build)
Build (2040) dB(A)
Difference (No Build to Build) Community
R10 B (67) 66 68 2 69 1 Darien
R11 C (67) 64 66 2 67 1 Darien
R12 B (67) 74 76 2 77 1 Darien
R13 B (67) 70 71 1 72 1 Darien
R14 C (67) 75 76 1 77 1 Darien
R15 B (67) 62 64 2 66 2 Darien
R16 B (67) 67 68 1 70 2 Darien
R17 C (67) 65 67 2 68 1 Darien
R18 E (72) 68 70 2 71 1 Woodridge
R19 C (67) 66 68 2 68 0 Darien
R20 B (67) 70 72 2 73 1 Darien
R21 B (67) 71 72 1 74 2 Darien
R22 B (67) 70 72 2 73 1 Darien
R23 E (72) 61 62 1 64 2 Darien
R24 B (67) 62 64 2 65 1 Darien
R25 B (67) 68 70 2 71 1 Darien
R26 B (67) 68 70 2 71 1 Darien
R27 B (67) 73 75 2 75 0 Darien
R28 B (67) 70 71 1 72 1 Willowbrook
R29 B (67) 70 72 2 73 1 Willowbrook
R30 B (67) 67 69 2 69 0 Willowbrook
R31 C (67) 63 65 2 65 0 Willowbrook
R32 B (67) 69 71 2 71 0 Willowbrook
R33 B (67) 71 73 2 73 0 Darien
R34 B (67) 71 72 1 73 1 Willowbrook
R35 B (67) 61 62 1 63 1 Willowbrook
R36 B (67) 68 70 2 71 1 Burr Ridge
R37 E (72) 65 67 2 68 1 Willowbrook
R38 B (67) 69 71 2 72 1 Willowbrook
R39 E (72) 59 61 2 62 1 Willowbrook
R40 E (72) 65 67 2 68 1 Willowbrook
R41 E (72) 66 68 2 69 1 Burr Ridge
R42 E (72) 72 74 2 75 1 Burr Ridge
R43 B (67) 68 69 1 71 2 Burr Ridge
R44 C (67) 63 65 2 66 1 Burr Ridge
R45 B (67) 63 65 2 66 1 Burr Ridge
R46 E (72) 70 72 2 73 1 Burr Ridge
R47 B (67) 61 62 1 63 1 Burr Ridge
R48 E (72) 60 62 2 63 1 Burr Ridge
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Receptor Number
Activity Category
(NAC dB[A])
Existing dB(A)
No Build (2040) dB(A)
Difference (Existing to No Build)
Build (2040) dB(A)
Difference (No Build to Build) Community
R49 E (72) 68 68 0 70 2 Burr Ridge
R50 B (67) 68 69 1 70 1 Indian Head Park
R51 B (67) 61 61 0 60 -1 Burr Ridge
R52 B (67) 62 63 1 64 1 Burr Ridge
R53 B (67) 70 72 2 72 0 Indian Head Park
R54 B (67) 64 65 1 65 0 Countryside
R55 C (67) 59 60 1 60 0 Countryside
R56 E (72) 58 58 0 59 1 Countryside
R57 B (67) 62 63 1 63 0 Countryside
R58 B (67) 75 78 3 77 -1 Countryside
R59 B (67) 75 77 2 77 0 Countryside
R60 E (72) 73 75 2 74 -1 Countryside
R61 C (67) 65 68 3 67 -1 Countryside
R62 B (67) 69 72 2 71 -1 Countryside
R63 B (67) 67 69 2 69 0 Countryside
R64 B (67) 62 64 2 63 -1 Hodgkins
R65 B (67) 65 67 2 67 0 Hodgkins
R66 C (67) 63 65 2 64 -1 Summit
R67 B (67) 66 68 2 67 -1 Summit
R68 C (67) 63 64 1 64 0 Chicago
R69 B (67) 63 65 2 64 -1 Chicago
R70 B (67) 60 61 1 61 0 Chicago
R71 C (67) 66 68 2 68 0 Chicago
R72 B (67) 56 57 1 57 0 Chicago
R73 C (67) 62 64 2 64 0 Chicago
R74 B (67) 62 64 2 64 0 Chicago
R75 B (67) 63 65 2 64 -1 Chicago
R76 B (67) 63 64 1 64 0 Chicago
R77 B (67) 61 63 2 63 0 Chicago
R78 C (67) 55 57 2 57 0 Chicago
R79 B (67) 71 72 1 72 0 Chicago
R80 B (67) 66 68 2 67 -1 Chicago
R81 B (67) 65 67 2 66 -1 Chicago
R82 B (67) 61 63 2 62 -1 Chicago
R83 B (67) 63 65 2 64 -1 Chicago
R84 B (67) 62 63 1 63 0 Chicago
R85 B (67) 62 64 2 63 -1 Chicago
R86 B (67) 64 66 2 65 -1 Chicago
R87 B (67) 62 64 2 63 -1 Chicago
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Receptor Number
Activity Category
(NAC dB[A])
Existing dB(A)
No Build (2040) dB(A)
Difference (Existing to No Build)
Build (2040) dB(A)
Difference (No Build to Build) Community
R88 B (67) 60 62 2 62 0 Chicago
R89 B (67) 56 58 2 57 -1 Chicago
R90 B (67) 60 61 1 60 -1 Chicago
R91 B (67) 59 61 2 60 -1 Chicago
R92 B (67) 65 67 2 65 -2 Chicago
R93 B (67) 62 64 2 62 -2 Chicago
R94 B (67) 60 62 2 60 -2 Chicago
R95 B (67) 76 78 2 79 1 Chicago
R96 B (67) 66 66 0 69 3 Chicago
R97 B (67) 66 66 0 69 3 Chicago
R98 B (67) 56 57 1 59 2 Chicago
R99 B (67) 66 67 1 70 3 Chicago
R100 B (67) 61 63 2 63 1 Chicago
R101 B (67) 57 59 2 61 2 Chicago
R102 B (67) 54 55 1 56 1 Chicago
R103 B (67) 61 63 2 65 2 Chicago
R104 B (67) 61 63 2 66 3 Chicago
R105 B (67) 59 60 1 62 2 Chicago
R106 B (67) 63 64 1 67 3 Chicago
R107 B (67) 57 58 1 60 2 Chicago
R108 B (67) 71 72 1 72 0 Chicago
R109 B (67) 59 60 1 60 0 Chicago
R110 B (67) 58 60 2 61 1 Chicago
R111 C (67) 59 61 2 60 -1 Chicago
R112 B (67) 53 55 2 56 1 Chicago
R113 B (67) 53 54 1 55 1 Chicago
R114 B (67) 54 56 2 56 0 Chicago
R115 B (67) 56 57 1 58 1 Chicago
R116 B (67) 56 57 1 57 0 Chicago
A shaded cell with bold text in the “Build (2040) dB(A)” column indicates that the noise level approaches [-1 db(A)], meets, or exceeds the NAC in the future build condition, constituting a noise impact.
Observations and Conclusions
As shown in Table 4, existing noise levels range from 53 dB(A) at R113 to 76 dB(A) at R95. Projected No Build 2040 traffic noise levels range from 54 dB(A) at R113 to 78 dB(A) at R95. The majority of receptors show a 1 to 2 dB(A) increase from Existing to No Build (2040) conditions, with select receptors experiencing a 3 dB(A) increase. Build (2040) condition levels range from 55 dB(A) at R113 to 79 dB(A) at R95. TNM-predicted noise levels for the Build (2040) condition range from a 2 dB(A) decrease to a 3 dB(A) increase over No Build (2040) levels. Across all 116 representative receptors, the average overall sound level change from the No Build condition to the Build condition is 0 dB(A). Build traffic noise levels were found to decrease
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
from the No Build condition for approximately 22% of representative receptors. In most instances, this is due to the effect of moving a designated portion of the projected future (2040) traffic from the three existing lanes of travel to a fourth lane (i.e., the managed lane, on the median side of the three existing lanes), effectively further from adjacent noise-sensitive receptors. At the northern (Chicago) end of the project, where I-55 is on elevated structure, the added lane along the I-55 median has the added effect of increasing the acoustic shielding for receptors situated below roadway grade. Under Build (2040) conditions, 57 of the 116 (49%) representative receptor locations approach, meet, or exceed the FHWA NAC, and therefore warrant a noise abatement analysis. None of the representative receptors are considered impacted due to a substantial increase (greater than 14 dB(A) increase) in traffic noise levels between the Existing and Build condition. Representative receptors with a predicted noise impact are identified in Table 4. Table 5 further summarizes the relative noise level differences between No Build (2040) levels and Build (2040) levels, reporting the change in dB(A) and providing a description of how the human ear would perceive that level of noise change. Commonly accepted principles regarding perception of noise level changes, as cited in the IDOT Highway Traffic Noise Assessment Manual, include:
± 10 dB(A) a doubling or halving of perceived noise level ± 5 dB(A) readily perceptible change ± 3 dB(A) barely perceptible change ± 1 dB(A) less than barely perceptible change
TABLE 5
PERCEPTABLE NOISE CHANGES FROM NO BUILD (2040) TO BUILD (2040) CONDITIONS
Noise Level Perception dB(A) Instances Among the Representative Receptors
Readily Perceptible >= +5 0
Barely Perceptible >= +3 5
Less than Barely Perceptible 2 to -2 111
Barely Perceptible <= -3 0
Readily Perceptible <= -5 0
Total 116
The table indicates that noise levels of the Build (2040) condition would generally be perceived by the human ear similarly to those of the year No Build (2040) condition. Furthermore, neither would result in a readily perceptible increase (or decrease) in noise. SECTION 7: ABATEMENT ANALYSIS Abatement Alternatives
Traffic noise abatement measures were considered for the impacted representative receptors that approach, meet, or exceed the appropriate FHWA NAC. The most feasible approach to abating noise impacts in these areas would be to construct a noise barrier, which may include a noise wall, an earth berm, or a combination of both. Noise walls are the most practical measure for this project, as most potential abatement locations require placement on structure or in locations
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
where existing constraints (such as local roadways) do not accommodate the wider footprint associated with earth berms. Noise abatement analysis is completed for all receptors represented within each CNE containing an impacted representative (worst-case noise condition) receptor.4 An effective noise barrier must be tall enough to break the line-of-sight between the receptor and source and typically extends beyond the last receptor four times the distance between the receptor and noise barrier. Noise barriers have a zone of effectiveness, or shadow zone, which is generally within 200 feet of the noise barrier; therefore, less noise reduction is achieved as the distance between the receptor and the noise barrier increases. TNM was used to perform the noise barrier feasibility and reasonability evaluation for the impacted representative receptors. When determining if an abatement measure is feasible and reasonable, the noise reductions achieved, number of represented receptors benefited, total cost, and total cost per represented receptor benefited are considered. Feasibility and Reasonableness
An analysis of noise abatement measures (noise barriers) was conducted in conformance with FHWA requirements contained in Title 23 Code of Federal Regulations Part 772 for each of the impacted representative receptors. In order for a noise abatement measure to be constructed, it must meet both the feasibility and reasonableness criteria, described below: Feasibility The feasibility evaluation is a combination of acoustical and engineering factors considered in the evaluation of a noise abatement measure. The acoustical portion of the IDOT policy, as required by FHWA regulations, considers noise abatement to be feasible if it achieves at least a 5 dB(A) traffic noise reduction at an impacted receptor. Factors including but not limited to safety, barrier height, topography, drainage, utilities, maintenance, and access issues also are considered. Reasonableness As per FHWA regulations, a noise abatement measure is determined to be reasonable when all three of the following reasonableness evaluation factors are met:
• cost-effectiveness of the highway traffic noise abatement measure; • achievement of IDOT’s noise reduction design goal, and • consideration of the viewpoints of the benefited receptors (property owners and residents)
results in a majority desiring the abatement The IDOT noise reduction design goal is to achieve an 8 dB(A) traffic noise reduction at a minimum of one benefited receptor. A noise abatement measure is considered cost-effective to construct if the noise barrier construction cost per benefited receptor is less than the allowable cost per benefited receptor. A benefited receptor is any receptor that is afforded at least a 5 dB(A) traffic noise reduction from the proposed noise abatement measure. FHWA regulations allow each State Highway Authority to establish cost criteria for determining cost effectiveness. IDOT policy establishes that the actual cost per benefited receptor shall be based on a noise barrier cost of $25 per square foot, which includes engineering, materials, and construction. The base value allowable cost is $24,000 per benefited receptor, which can be increased based on three factors as summarized below:
4 In the abatement analysis section of the report, all instances of “receptor,” unless otherwise noted, are represented receptors.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
• the absolute noise level of the benefited receptors in the design year build scenario before noise abatement;
• the incremental increase in noise level between the existing noise level at the benefited receptor and the predicted build noise level before noise abatement; and
• the date of development compared to the construction date of the highway. These factors are considered for all benefited receptors.
Absolute Noise Level Consideration
Predicted Build Noise Level Before Noise Abatement
Dollars Added to Base Value Cost per Benefited Represented Receptor
Less than 70 dB(A) $0
70 to 74 dB(A) $1,000
75 to 79 dB(A) $2,000
80 dB(A) or greater $4,000 Source: IDOT Highway Traffic Noise Assessment Manual
Increase in Noise Level Consideration
Incremental Increase in Noise Level Between the Existing Noise Level and the Predicted Build Noise Level Before Noise
Abatement
Dollars Added to Base Value Cost per Benefited Represented Receptor
Less than 5 dB(A) $0
5 to 9 dB(A) $1,000
10 to 14 dB(A) $2,000
15 dB(A) or greater $4,000 Source: IDOT Highway Traffic Noise Assessment Manual
New Alignment / Construction Date Consideration
Project is on new alignment OR the receptor existed prior to the original
construction of the highway
Dollars Added to Base Value Cost per Benefited Represented Receptor
No for both $0
Yes for either $5,000
Source: IDOT Highway Traffic Noise Assessment Manual NOTE: No single optional reasonableness factor shall be used to determine that a noise abatement measure is unreasonable.
If a noise abatement measure is feasible, achieves the cost-effective criterion, and achieves the IDOT noise reduction design goal, the viewpoints of benefited receptors are then solicited regarding construction of the noise barrier. Noise Barrier Analysis
TNM was used to perform the noise barrier feasibility and reasonableness check for CNEs with an impacted representative receptor. When determining if an abatement measure is feasible and reasonable, the noise reductions achieved, number of residences benefited, total barrier cost, and total cost per residence benefited are considered. The noise barriers studied in the abatement analysis are displayed on Figure 3 (Appendix A).
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Existing Noise Barriers The project corridor contains three existing noise barriers (B2, B10, and B15) constructed along I-55 in the project corridor (within the villages of Lemont, Burr Ridge, Countryside), and one constructed along I-294 near its I-55 overpass (located in the Village of Countryside). Seven representative receptors situated in the shadow zone of B2, B10, and B15 (R3, R51, R52, R54, R55, R56, and R57) were selected for inclusion in the TNM analysis for this study (along with the barriers themselves). None of these seven receptors were predicted to experience traffic noise impacts. New Noise Barriers Evaluated Seventeen noise barriers were evaluated for representative receptors with predicted Build (2040) condition impacts (see Table 4 in Section 6). Each of these seventeen barriers were found to be feasible, meaning they could achieve at least a 5 dB(A) reduction at an impacted receptor. Sixteen of the seventeen meet the first criterion of reasonableness by achieving the IDOT noise reduction design goal of at least an 8 dB(A) traffic noise reduction at one or more benefited receptors. These sixteen barriers were then evaluated for cost-effectiveness. Table 6 summarizes the results of the adjusted allowable cost per benefited receptor determination. Table 7 summarizes the results of the noise abatement evaluation.
TABLE 6
ADJUSTED ALLOWABLE COST PER BENEFITED RECEPTOR
Barrier Corresponding Representative
Receptor(s)
Number of Benefitted Receptors
Adjustment Factor Range
Adjusted Allowable Cost per Benefited Receptor
B1 R1, R2 92 $0 $24,000
B3 R4-R17 197 $0-$2,000 $24,273
B4 R18-R22 218 $0-$2,000 $24,177
B5 R23-R25 127 $0-$1,000 $24,969
B6 R26-R31 151 $0-$2,000 $24,524
B7 R32-R38 82 $0-$2,000 $24,561
B8 R42-R44 30 $0-$1,000 $24,070
B9 R45-R48 318 $0-$1,000 $24,379
B11 R50 1 $1,000 $25,000
B12 Does Not Meet IDOT Noise Reduction Design Goal
B14-B16 R58-R62 19 $0-2,000 $24,895
B17 R63 6 $0 $24,000
B18 R64, R65 113 $0 $24,000
B19 R66, R67 82 $0 $24,000
B20 R79-R94 335 $0-$1,000 $24,173
B21 R95-R116 396 $0-$1,000 $24,171
B23 R70-R71 4 $0 $24,000
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
TABLE 7 NOISE ABATEMENT ANALYSIS SUMMARY
Barrier Location of Barrier Along I-55 Barrier Length (ft) 1
Barrier Height (ft) 1
Barrier Construction
Cost 2
Total Allowable Barrier Cost 3
Benefitted Represented Receptors 4
Adjusted Allowable Cost per Benefitted
Receptor
Actual Cost per Benefitted Receptor
Ratio 5 Finding
B1 North Side, Between I-355 and Lemont Rd. 5,145 14 $1,800,750 $2,208,000 92 $24,000 $19,573 0.82 Cost-Effective
B3 North Side, Between Lemont and S. Cass Rd. 9,864 16 $3,945,600 $4,781,696 197 $24,273 $20,028 0.83 Cost-Effective
B4 South Side, Between Lemont and S. Cass Rd. 7,008 13 $2,277,600 $5,270,586 218 $24,177 $10,448 0.43 Cost-Effective
B5 North Side, along Ramp to Northbound Lemont Rd. 2,027 14 $709,450 $3,171,063 127 $24,969 $5,586 0.22 Cost-Effective
B6 North Side, Between S. Cass and Kingery Hwy. 5,380 14 $1,883,000 $3,703,170 151 $24,524 $12,470 0.51 Cost-Effective
B7 South Side, Between S. Cass and Kingery Hwy. 6,231 14-16 $2,382,475 $2,014,000 82 $24,561 $29,055 1.18 Not Cost-Effective (Not Reasonable)
B8 North Side, Between Kingery Hwy. and County Line Rd. 2,403 12-16 $857,250 $722,114 30 $24,070 $28,575 1.19 Not Cost-Effective
(Not Reasonable)
B9 South Side, Between S. Cass & County Line Rd. 3,346 21 $1,809,150 $7,752,616 318 $24,379 $5,689 0.23 Cost-Effective
B11 North Side at Wolf Road Overpass 900 16 $360,000 $25,000 1 $25,000 $360,000 14.40 Not Cost-Effective (Not Reasonable)
B12 Along Northbound Exit Ramp to I-294 South Does Not Meet IDOT Design Goal Not Reasonable
B14/B16 South Side, at Willow Springs Rd. (B14) & Along Ramp from NB I-294 to NB I-55 (B16) 1,735/1,322 11/14 $939,825 $473,005 19 $24,895 $49,464 1.99 Not Cost-Effective
(Not Reasonable)
B17 South Side, just South of La Grange Rd. 1,730 16 $692,000 $144,000 6 $24,000 $115,333 4.81 Not Cost-Effective (Not Reasonable)
B18 Along Southbound Exit Ramp to La Grange Rd. 1,760 13 $572,000 $2,712,000 113 $24,000 $5,062 0.21 Cost-Effective
B19 Along Northbound Exit Ramp to S. Harlem Rd. 2,258 14 $790,300 $1,968,000 82 $24,000 $9,638 0.40 Cost-Effective
B20 North Side, just west of I-90/94 7,077 10 $1,769,250 $8,097,960 335 $24,173 $5,281 0.22 Cost-Effective
B21 South Side, just west of I-90/94 6,670 10 $1,667,500 $9,571,610 396 $24,171 $4,211 0.17 Cost-Effective
B23 South Side, between S. Central Ave. & Cicero 1,351 17 $574,175 $96,000 4 $24,000 $143,544 5.98 Not Cost-Effective (Not Reasonable)
1 Barrier length and height are not listed for barriers that are not reasonable and feasible. 2 Based on the IDOT policy value of $25 per square foot 3 Per IDOT traffic noise policy and the reasonableness analysis 4 Any receptor receiving at least a 5 dB(A) reduction due to the proposed barrier 5 Ratio of actual build cost of a barrier per benefitted receptor to the adjusted allowable cost per benefitted receptor; this is used to determine if a barrier can be found cost effective
through cost averaging. For a single noise abatement measure to be considered as part of a cost averaging solution, this ratio must not exceed 2.0 (the cost of noise abatement per benefitted receptor may not exceed two times the adjusted noise abatement cost per benefitted receptor).
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Sixteen noise barriers which were found to be feasible and achieve the IDOT noise reduction design goal were evaluated for cost-effectiveness, and six were found to be not cost-effective (B7, B8, B11, B14/B16, B17, and B23). The ten remaining noise barriers (B1, B3, B4, B5, B6, B9, B18, B19, B20, and B21) were found to be reasonable as stand-alone barriers. Cost Averaging After the noise barrier locations were considered reasonable or feasible as stand-alone barriers, the noise barrier costs were then considered cumulatively, across CNEs, to determine if any barrier found to be not cost-effective standing alone could be cost-effective cumulatively. As shown in Table 8, the cost averaging analysis places analyzed barriers in order of increasing cost effective ratio (ratio between the actual cost per benefited receptor and the adjusted allowable cost per benefited receptor). Noise abatement measures achieve the cost reasonableness criterion cumulatively if the cumulative estimated noise barrier cost per benefited receptor is less than the cumulative adjusted allowable cost per benefited receptor, when considering all barriers that are feasible and meet the noise reduction design goal. Table 10 summarizes the cost averaging analysis. Considering the noise barriers on a cumulative basis, three additional noise barriers would be considered cost-effective (B7, B8, and B14/B16):
TABLE 8 COST AVERAGING ANALYSIS SUMMARY
Barrier Number
Benefited Represented
Receptors
Noise Barrier
Cost
Actual Cost per
Benefited Receptor
Adjusted Allowable Cost per
Benefited Receptor
Ratio of Est. Build / Adjust.
Allowable
Cumulative Estimated
Build Cost / Benefited
Cumulative Adjusted Allowable
Cost / Benefited
Result of Determination
B21 396 $1,667,500 $4,211 $24,171 0.17 $4,211 $24,171 Cost Effective Stand Alone
B18 113 $572,000 $5,062 $24,000 0.21 $4,400 $24,133 Cost Effective Stand Alone
B20 335 $1,769,250 $5,281 $24,173 0.22 $4,750 $24,149 Cost Effective Stand Alone
B5 127 $709,450 $5,586 $24,969 0.22 $4,859 $24,256 Cost Effective Stand Alone
B9 318 $1,809,150 $5,689 $24,379 0.23 $5,064 $24,286 Cost Effective Stand Alone
B19 82 $790,300 $9,638 $24,000 0.40 $5,337 $24,269 Cost Effective Stand Alone
B4 218 $2,277,600 $10,448 $24,177 0.43 $6,039 $24,257 Cost Effective Stand Alone
B6 151 $1,883,000 $12,470 $24,524 0.51 $6,597 $24,280 Cost Effective Stand Alone
B1 92 $1,800,750 $19,573 $24,000 0.82 $7,248 $24,266 Cost Effective Stand Alone
B3 197 $3,945,600 $20,028 $24,273 0.83 $8,489 $24,266 Cost Effective Stand Alone
B7 82 $2,382,475 $29,055 $24,561 1.18 $9,288 $24,278 Cost Effective Cumulatively
B8 30 $857,250 $28,575 $24,070 1.19 $9,558 $24,275 Cost Effective Cumulatively
B14/B16 19 $939,825 $49,464 $24,895 1.99 $9,909 $24,280 Cost Effective Cumulatively
B17 6 $692,000 $115,333 $24,000 4.81 Not included in evaluation; Estimated cost is greater than
two times the adjusted allowed cost B23 4 $574,175 $143,544 $24,000 5.98
B11 1 $360,000 $360,000 $25,000 14.40
B12 Does Not Meet IDOT Noise Reduction Design Goal
Based on the traffic noise analysis and noise abatement evaluation conducted, highway traffic noise abatement measures are likely to be implemented based on preliminary design. The noise barriers determined to meet the feasible and reasonableness criteria are identified in Table 8
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
(above). If it subsequently develops during final design that constraints not foreseen in the preliminary design occur, or public input substantially changes reasonableness, the abatement measure may need to be modified or removed from the project plans. A final decision on the installation of abatement measure(s) will be made upon completion of project’s final design and the public involvement process. SECTION 8: PERMITTING OF PLANNED DEVELOPMENTS A residential development is planned for a currently-undeveloped area situated along South Frontage Road, between Burr Ridge Parkway and Commonwealth Avenue in the Village of Burr Ridge. This development has not yet been permitted as of the completion of the Environmental Assessment. However, in accordance with Section 3.4 of the IDOT noise manual, TNM analysis was performed for this location in the event that the development received a permit prior to the environmental approval of the project. The TNM analysis predicts a Build-condition noise impact at this planned development, prompting the evaluation of a potential noise barrier for this location. The potential barrier would connect to an existing noise barrier (B10) constructed along the ramp from northbound I-55 to northbound I-294, which serves the CNE represented by R51. TNM barrier evaluation determines that a noise wall measuring 17 feet in height and 1,300 feet in length would meet the IDOT design goal of providing an 8 dB(A) reduction for a least one receptor in the planned development, and provide a minimum 5 dB(A) reduction (benefit) for a total of 17 receptors. This barrier would not be cost-reasonable on a stand-alone basis, but would be considered cumulatively cost-reasonable as part of cost averaging.
Further coordination with the Village of Burr Ridge has subsequently determined that the planned development will not be permitted prior to completion of the project Environmental Document. Therefore, the potential barrier for this location was eliminated from further consideration and the planned development site will be considered an undeveloped land (see Section 9). Correspondence regarding this planned development is included in Appendix B. SECTION 9: COORDINATION WITH LOCAL OFFICALS FOR UNDEVELOPED LANDS Undeveloped parcels occur along I-55 in the project corridor, located in the communities of Darien, Willowbrook, Burr Ridge, Indian Head Park, Hodgkins, and Chicago, and in unincorporated areas of DuPage County. For local agency planning and development purposes, TNM analysis of project Build-condition sound levels was conducted for these undeveloped lands. This analysis is a worst-case assessment, assuming no presence of noise barriers at undeveloped parcels (none of these parcels are shielded by existing noise barriers, however some are located in areas where this noise analysis finds new noise barriers to be feasible and reasonable). The following table lists the approximate distances (from proposed I-55 mainline edge of pavement) where Build-condition sound levels are predicted to approach, meet, or exceed the applicable NAC for Activity Category B/C and Activity Category E land uses:
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Summary of Build (2040) Sound Levels for Undeveloped Parcels
Parcel Approaches, Meets, or Exceeds
Activity Category B/C NAC of 67 dB(A) (Measured from I-55 Edge of Pavement)
Approaches, Meets, or Exceeds Activity Category E NAC of 72 dB(A)
(Measured from I-55 Edge of Pavement)
DuPage County (A) 300 feet Does Not Approach
DuPage County (B) Within 425 feet Within 250 feet
DuPage County (C) Within 225 feet Within 150 feet
DuPage County (D) Within 475 feet Within 150 feet
Darien (A) Entire Parcel Entire Parcel
Darien (B) Entire Parcel Within 250 feet
Darien (C) Within 400 feet Does Not Approach
Willowbrook Entire Parcel Within 175 feet
Burr Ridge (A) Within 450 feet Within 200 feet
Burr Ridge (B) Entire Parcel Entire Parcel
Burr Ridge (C) Within 275 feet Within 175 feet
Burr Ridge (D) Within 225 feet Within 125 feet
Indian Head Park Entire Parcel Does Not Approach
Hodgkins (A) Within 225 feet Does Not Approach
Hodgkins (B) Does Not Approach Does Not Approach
Chicago (A) Does Not Approach Does Not Approach
Chicago (B) Within 250 feet Does Not Approach
Chicago (C) Entire Parcel Does Not Approach
Chicago (D) Does Not Approach Does Not Approach
Chicago (E) Within 100 feet Does Not Approach
Chicago (F) Does Not Approach Does Not Approach
Chicago (G) Within 225 feet Does Not Approach
Chicago (H) Does Not Approach Does Not Approach
Chicago (I) Does Not Approach Does Not Approach
Chicago (J) Does Not Approach Does Not Approach
Chicago (K) Does Not Approach Does Not Approach
Appendix B includes letters to be sent to local officials having jurisdiction over these adjacent undeveloped lands, and an exhibit (as an attachment to the letter) depicting the approximate distances where the applicable NAC is approached, met, or exceeded. SECTION 10: CONSTRUCTION NOISE Trucks and machinery used for construction produce noise that may affect some land uses and activities during the construction period. Residents along the alignment will at some time experience perceptible construction noise from implementation of the project. To minimize or eliminate the effect of construction noise on these areas, mitigation measures have been incorporated into the Illinois Department of Transportation’s Standard Specifications for Road and Bridge Construction as Article 107.35.
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
SECTION 11: VIEWPOINT SOLICITATION SUMMARY A Viewpoint solicitation was conducted to provide input from the benefited receptors in deciding the implementation of the identified noise walls. The process is consistent with Illinois Department of Transportation policies. As part of the Viewpoint Solicitation an extensive community outreach and education plan was conducted to support the Viewpoint voting process.
Agency Coordination
Meetings were conducted with municipal leaders, DuPage County and the Forest Preserve District of DuPage County to identify the location of potential noise walls and describe the Viewpoint Solicitation process. A summary of these meetings can be found in Appendix C.
Noise Forums
Noise forums were conducted at three locations along the project corridor. Post cards were sent to benefited receptors inviting them to these forums at which potential noise wall locations were identified along with additional project information. The Viewpoint Solicitation process was presented and project staff was available to answer question. A summary of these Noise Forums can be found in Appendix C.
Viewpoint Solicitation
The first Viewpoint Solicitation was mailed out to benefited receptors on May 4, 2016. Solicitations for Barriers B20 and B21 were sent to each benefited receptor in English, Spanish and Chinese in order to maximize the outreach to the local communities at these locations. A second Viewpoint Solicitation was mailed out for B-5, B-20 and B-21 on June 6, 2016. A copy of the Viewpoint Solicitation letter and Ballot can be found in Appendix C. Following is a tabular summary of the Viewpoint Solicitation for each barrier location which shows that three barriers (B5, B21 and B21) required a second solicitation. As a result of the final Solicitation, 12 barriers (B1, B3, B4, B5, B6, B7, B8, B14-16, B18, B19, B20 and B21) have been approved and one (B9) has been rejected. Copies of returned ballots are included in Appendix C.
TABLE 9
VIEWPOINT SOLICITATION SUMMARY
Barrier Number
Benefited Receptors
Total Possible
Votes
Forms Returned
Respond Rate
Total Votes Cast
Support Barrier
Against Barrier
B1 92 92 78 85% 78 76 2
B3 197 203 151 77% 152 147 5
B4 218 218 79 36% 79 73 6
B5* 127 254 2 2% 4 4 0
B6 151 163 81 54% 82 78 4
B7 82 94 28 34% 35 33 2
B8 30 31 15 50% 15 14 1
B9 318 332 125 39% 127 8 119
B14/B16 19 29 11 58% 17 17 0
B18 113 226 60 53% 60 57 3
B19 82 82 30 37% 30 24 6
B20* 335 395 131 39% 131 109 22
B21* 396 623 189 48% 228 134 94
Total 2160 2742 980 45% 1038 774 264
* Second Solicitation Required
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I-55 Managed Lane Phase I Study Traffic Noise Analysis July 2016
Viewpoint Solicitation Comments As part of the viewpoint solicitation process, a number of ballots were returned with comments. These comments have been summarized and are included in Appendix C. Viewpoint Solicitation Notification At the completion of the viewpoint solicitation process, all benefited receptors will be notified of the results for their specific barrier via USPS and the information will be available on the project website. SECTION 12: CONCLUSION This traffic noise study has been coordinated to evaluate traffic noise impacts for the proposed improvements to I-55 (Stevenson Expressway) from I-355 (Veterans Memorial Tollway) to I/90/94) (Dan Ryan Expressway). Traffic noise was evaluated at 116 representative receptor locations. Existing noise levels range from 53 dB(A) to 76 dB(A); projected No Build (2040) traffic noise levels range from 54 dB(A) to 78 dB(A). The majority of receptors show a 1-2 dB(A) increase from Existing to No Build (2040) conditions, with select receptors experiencing a 3 dB(A) increase. Build (2040) condition traffic noise levels range from 55 dB(A) to 79 dB(A). A total of 57 of 116 (49%) representative receptors approach, meet, or exceed the FHWA NAC, and therefore warrant a noise abatement analysis. None of the representative receptors are considered impacted due to a substantial increase in noise level. Seventeen noise barriers were evaluated for the abatement of impacts predicted for representative receptors under project Build conditions. All seventeen of these barriers met IDOT’s feasibility criterion, and sixteen achieved IDOT’s noise reduction design goal of at least an 8 dB(A) traffic noise reduction at one or more benefited receptor locations. The sixteen barriers that achieved the IDOT noise reduction design goal were then evaluated for economic reasonableness, and ten met this criterion. A subsequent cost-averaging analysis resulted in the cumulative inclusion of three additional barriers which were not found to be cost-effective on a stand-alone basis. Therefore, based on the traffic noise analysis and noise abatement evaluation, highway traffic noise abatement measures are deemed feasible and reasonable for implementation at thirteen locations based on preliminary design. These thirteen noise barriers are identified in Table 8, and are shown on Figure 3. The Viewpoint Solicitation has resulted in 12 barriers approved and 1 barrier rejected by the benefited receptors. Should unforeseen constraints occur during final design, or should public input substantially change reasonableness, an abatement measure may need to be modified or removed from the project plans. A final decision on the installation of abatement measures will be made upon completion of project’s final design and the public involvement process.
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