Traffic Noise Analysis 599...eq equivalent noise level NAC noise abatement criteria NMDOT New Mexico...

Durango, CO

Pagosa Springs, CO

Albuquerque, NM

Farmington, NM

October 2019

Traffic Noise Analysis NM 599-US 84/285 On-ramp

Improvements

Milepost 165.5 to MP 166.5

Santa Fe County – New Mexico

Control Number S100430

Prepared for:

Radian Engineering, LLC 509 Camino de los Marquez, Suite 2 Santa Fe, New Mexico 87501 On Behalf of New Mexico Department of Transportation and Federal Highway Administration

Prepared by: Ecosphere Environmental Services, Inc. 320 Osuna Road NE Building C, Suite C-1 Albuquerque, New Mexico 87107 505-954-1570

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Traffic Noise Analysis: NM 599-US 84/285 On-ramp Improvements

Ecosphere Environmental Services, Inc.

TY Lin International | October 2018 i

Table of Contents

1. Introduction ................................................................................................................................... 1

2. Federal Highway Administration/New Mexico Department of Transportation Noise Policies and Procedures ........................................................................................................................................ 3

3. Existing Conditions ......................................................................................................................... 4

4. Measurement/Model Comparison (Validation) ............................................................................... 6

5. Model Input Data ........................................................................................................................... 7

6. Traffic Noise Modeling: No-Build Scenario ...................................................................................... 7

7. Evaluation of Impacts: Build Scenario ............................................................................................. 8

8. Conclusions .................................................................................................................................. 10

9. References ................................................................................................................................... 10

List of Tables

Table 1. Noise abatement criteria from 23 Code of Federal Regulations, Part 772 (average A-weighted

decibels [dBA Leq]) ......................................................................................................................................... 3

Table 2. Validation traffic volumes (vehicles per hour) and noise levels (dBA Leq) ...................................... 6

Table 3. Existing and future traffic volumes (vehicles per hour) .................................................................. 7

Table 4. Existing and future no-build noise-modeling results (average A-weighted decibels [dBA Leq]) ..... 8

Table 5. Future build noise modeling results (average A-weighted decibels [dBA Leq]) ............................... 9

Table 6. Balcony Height: Future build noise modeling results (average A-weighted decibels [dBA Leq]) .... 9

List of Figures

Figure 1. Project Location and Site Detail Map ............................................................................................. 2

Traffic Noise Analysis: NM 599-US 84/285 On-ramp Improvements Ecosphere Environmental Services, Inc.

ii Radian Engineering LLC | October 2019

Abbreviations and Acronyms

dB decibel dBA A-weighted decibel Ecosphere Ecosphere Environmental Services, Inc. FHWA Federal Highway Administration Leq equivalent noise level NAC noise abatement criteria NMDOT New Mexico Department of Transportation NM 599 New Mexico State Highway 599 Project NM 599-US 84/285 On-ramp Improvements TNM Traffic Noise Model US 84/285 U.S. Highway 84/285

Traffic Noise Analysis: NM 599-US 84/285 On-ramp Improvements

Ecosphere Environmental Services, Inc.

Radian Engineering | October 2019 1

1. Introduction

The New Mexico Department of Transportation (NMDOT) and Federal Highway Administration are

proposing to reconstruct the east to southbound on-ramp from New Mexico State Highway 599 (NM

599) to US Highway 84/285 (US 84/285) (Project) in the City of Santa Fe, New Mexico (see Figure 1). The

purpose of the Project is to improve visibility and increase the merge distance at this location and thus

enhance safety. The current topography (a low hill vegetated with small trees and shrubs) immediately

north of the NM 599 --US 84/285 gore point blocks visibility for merging vehicles on both facilities.

When vehicles on NM 599 pass this sight obstruction, they have a relatively short distance to merge

with high-speed southbound traffic on US 84/285. Similarly, traffic on US 84/285 does not see entering

traffic on NM 599 until only a short distance remains to complete the merge. The proposed Project

would address these conditions and also improve drainage, access, lighting, deteriorating guardrail, and

the center concrete wall barrier on US 84/285.

Funding for the proposed Project is identified in the Statewide Transportation Improvement Program

under Project/Control Number S100430. Currently, $2,400,620 (including Road Fund, STP FlexNC, and

National Highway Performance Program funding) is available in NMDOT District 5 for the Project.

Both NM 599 and US 84/285 are Principal Arterial highways. NM 599 currently consists of two 12-foot-

wide lanes with 10-foot-wide paved outside shoulders in each direction separated by a depressed

median. US 84/285 has two 12-foot-wide lanes southbound with a paved outside shoulder that varies in

width. Northbound US/84-285 has three 12-foot driving lanes, a paved outside shoulder, and is

separated from the southbound lanes by a concrete wall barrier. The existing NM 599 to US 84/285 on-

ramp has one 16-foot-wide lane with 4-foot-wide shoulders and curb and gutter on both sides.

The proposed Project would consist of reconstructing the southbound NM 599 on-ramp on an alignment

parallel to and slightly north and east of the current on-ramp. The new alignment would cut through and

eliminate the hilly terrain that currently blocks visibility between the ramp and mainline US 84/285 and

would improve the merge condition onto US 84/285. The new on-ramp would be approximately 2,500-

feet long with one 16-foot-wide lane, two 4-foot-wide shoulders, and curb and gutter.

The Project would also include drainage improvements consisting of a paved swale on the west side of

US 84/285. The swale would begin just south of the end of the on-ramp and extend approximately 850

feet south where it would be routed into an underground culvert and discharge into the Cañada Rincon

arroyo. Other Project improvements would include reconstruction of the center concrete wall barrier on

US 84/285, replacement of dilapidated metal guardrail, roadway striping, lighting, signing, and removal

of the existing access from Viento Drive to US 84/285.

The purpose of the following analysis is to evaluate the potential noise impacts of the Project in the

context of NMDOT and FHWA traffic noise policies and procedures. The current noise analysis follows

standard NMDOT and FHWA methodology, including measurements of existing noise and predictive

modeling of existing and future noise levels under the no-build and Project-build conditions.


2 Radian Engineering LLC | October 2019

Figure 1. Project Location and Site Detail Map


Radian Engineering LLC | October 2019 3

2. Federal Highway Administration/New Mexico Department of Transportation Noise Policies and Procedures

Because this Project uses FHWA and NMDOT funding, it must follow state and federal traffic noise

policies, including the NMDOT’s Infrastructure Design Directive IDD-2011-02: Procedures for Abatement

of Highway Traffic Noise and Construction Noise (NMDOT 2011) and the FHWA’s Highway Traffic Noise:

Analysis and Abatement Guidance (FHWA 2011). Under these guidelines, the relative loudness of noise

is described in decibels (dB), a measure of sound pressure on a logarithmic scale. For highway noise

studies, traffic noise is averaged over a 1-hour peak noise period and is expressed as an equivalent noise

level (Leq). An A-weighted filter is also used to correlate physical noise levels with the frequency

sensitivity of human hearing and the subjective response to noise. Thus, noise conditions are generally

discussed in terms of hourly average A-weighted noise levels in decibels, or dBA Leq.

The noise standards of the NMDOT and FHWA are based on a 1-hour dBA Leq, calculated during the peak

hour of traffic noise. According to FHWA and NMDOT procedures, noise abatement must be considered

when predicted traffic noise levels approach or exceed specified noise abatement criteria (NAC) defined

for various land-use categories or when predicted future noise levels exceed existing levels by 10 dBA or

more. NMDOT’s noise policy defines “approach” as being within 1-dBA of the appropriate NAC (Table 1).

Table 1. Noise abatement criteria from 23 Code of Federal Regulations, Part 772

(average A-weighted decibels [dBA Leq])

Activity Category

Activity Criteria

Activity Location

Activity Location

A 57 Exterior Lands on which serenity and quiet are of extraordinary significance and serve an important public need, and where preservation of those qualities is essential if the area is to continue to serve its intended purpose.

B 67 Exterior Residential.

C 67 Exterior Active sports areas, amphitheaters, auditoriums, campgrounds, cemeteries, daycare 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, daycare centers, hospitals, libraries, medical facilities, places of worship, public meeting rooms, public or nonprofit institutional structures, radio studios, recording studios, schools, and television studios.



Activity Category

Activity Criteria

Activity Location

Activity Location

E 72 Exterior Hotels; motels; offices; restaurants/bars; and other developed lands, properties, or activities not included in previous A-D or F activity categories.

F NA NA 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 NA NA Undeveloped lands that are not permitted.

Source: Federal Highway Administration 2011.

3. Existing Conditions

The Project area on the north side of the City of Santa Fe extends through vacant land with some areas

of high-density residential development. On the east side of US 84/285 is the Santa Fe National

Cemetery and a single-family residential development that is shielded by a noise wall constructed when

US 84/285 was improved in this area in 2000-2001. This area is not considered further.

On the west side of US 84/285, the primary noise areas include high-density residential development in

the Zocalo Condominiums, Reserve at Santa Fe Condominiums, Los Piñones Apartment Homes, and

other multi-family units around Viento Drive. Most of these are two story units and many have second

floor, outdoor balconies.

Just west of the ramp diverge point on NM 599, the road crosses the Cañada Rincon arroyo. The on-

ramp climbs in elevation to the US 84/285 merge, then drops in elevation to the south along US 84/285.

Cañada Rincon parallels US 84/285 to the west but for most of the length of the on-ramp, low hills and

an earthen berm are situated between the roadway and arroyo. This hilly, higher terrain is above the

road elevation and creates a visual and noise barrier between the highway and the Zocalo residential

development to the west. At about MP 165.9, the Cañada Rincon is immediately adjacent to the

embankment of US 84/285. In 2000-2001, a noise wall was constructed in this area at the edge of the

road because there is no room for a berm between the road and arroyo, and several residential

condominiums (Zocalo) are relatively close to the highway. As US 84/285 extends south from the noise

wall, the Cañada Rincon continues immediately west of the road and intervening terrain does not occur

between the highway and residential development west of the arroyo.

To evaluate noise impacts, ten receivers (sites where noise levels are modelled) were defined to

represent the residential areas most likely to be affected by Project noise. These are described below

and shown on Figure 1.



Receivers 1 and 2 represents a group of units in the Zocalo Condominiums toward the north end of the

development. These units are 250 to 310 feet from NM 599 near the existing ramp diverge point and are

exposed to traffic noise with no intervening terrain.

Receiver 3 is located at a mid-point along Avenida Rincon, which is the main north-south road through

Zocalo and provides access to multiple units, which are located on the west side of this street. These

range in distance from about 650 to 1,100 feet from the NM 599 on-ramp and US 84/285 mainline. All

are buffered from highway noise by terrain elevated above the highway.

Receiver 4 represents a newly developing area in the Zocalo Condominiums accessed from a

perpendicular street east of Avenida Rincon. The new units will be located about 450 feet west of US

84/285, near the southern merge point of the proposed on-ramp. The terrain in this area is elevated

above the highway and planned condominiums.

Receiver 5 represents Zocalo units at the end of Avenida Celaya, which is perpendicular to and east of

Avenida Rincon. This area is approximately 280 feet from the US 84/285 mainline, south of the on-ramp

merge point. Natural terrain is elevated above the highway and condominium units.

Receiver 6 represents units at the east end of Avenida Colima, which is also perpendicular to and east of

Avenida Rincon. Some of these units are only about 70 feet from the edge of the US 84/285 mainline;

however, they are situated below the elevation of the road and an earthen berm is situated between

the highway and residences. In addition to the elevation difference, the berm provides added

attenuation of noise from the highway.

Receiver 7 represents units on Circulo de Morelia at the southern end of the Zocalo Condominiums. The

nearest point to US 84/285 within this group of units is approximately 125 feet from the edge of the

highway. These units are shielded by the noise wall built at the time of the 2000-2001 US 84/285

improvements, which is approximately 185-feet long and 8- to 9-feet high.

Receiver 8 represents condominiums at the southern end of Avenida Morelia. The closest of these units

is about 250 feet from the edge of US 84/285 over unobstructed terrain. The existing noise wall does not

extend far enough south to shield this area from traffic noise from US 84/285.

Receiver 9 represents the cluster of units in the Reserve at Santa Fe Condominiums that is nearest to the

US 84/285 mainline, approximately 380 feet. This complex is west of the Cañada Rincon across

unobstructed terrain.

Receiver 10 represents the nearest units to the US 84/285 mainline in the apartments accessed from

Viento Drive and Calle Mejia. There are a large number of apartments in this area, including the Los

Piñones Apartment Homes, that are exposed to traffic noise over unobstructed terrain. The nearest unit

is approximately 280 feet from the US 84/285 mainline.



4. Measurement/Model Comparison (Validation)

NMDOT Design Directive IDD-2011-02 (2011) stipulates that noise analyses conducted for existing

alignments should use predictions (modeling) to determine existing and design year traffic noise impacts

(Section 5.00a2) and that predicted noise levels should be validated through comparison of measured

and predicted levels (Section 5.00a11). To compare predicted and measured noise levels, the FHWA’s

Traffic Noise Model (TNM) (Version 2.5) (FHWA 2004) was used with existing traffic counts and site

conditions to predict noise levels at a location where measurements were taken. Noise measurements

and simultaneous traffic counts were collected on August 28, 2019 from approximately 8:50 to 9:07

AM1. The measurement location was on the west side of US 84/285 just south of the NM 599 merge

point and approximately 30 feet from the edge of the southbound driving lane at the same grade as the

roadway. This location provided a direct line-of-sight to the roadway traffic lanes, allowing directional

traffic counts and classification of autos, medium trucks (two axles but more than four tires), and heavy

trucks (three or more axles). Average traffic speed was estimated at 65 miles per hour on US 84/285 by

driving with the flow of traffic in the corridor. The counts (converted to hourly totals) and

measurements are shown in Table 2.

Table 2. Validation traffic volumes (vehicles per hour) and noise levels (dBA Leq)

Count Location/Period Autos

Medium Trucks

Heavy Trucks

Measured Noise

Modeled Noise

Difference (Measured- Modeled) NB SB NB SB NB SB

US 84/285 Mainline August 28, 2019

818 1482 11 43 43 25 77.6 76.5 0.9

Note: NB=northbound; SB=southbound.

Existing noise levels were calculated for the measurement site using the TNM model with inputs that

matched the location and traffic conditions at the time of the measurements. The TNM model uses site-

specific information on traffic volumes and speeds, vehicle classifications, roadway geometry, and site

acoustical properties to predict hourly noise levels at selected locations. The measured and modeled

noise levels were compared to validate the assumptions used in the model. The August 2019 traffic and

site data were entered as inputs into the TNM model. The results are shown in Table 2 compared to the

measured noise levels. The modeled and measured levels vary slightly but are well within the generally

accepted tolerance of 3 dBA.

1 Statistical accuracy requires minimum measurements of approximately 8 minutes. Most highway agencies typically use 15-minute time periods to represent the Leq (FHWA 2011). Noise was measured using a Larson Davis Sound Track LxT1, Type I Integrating Sound Level Meter (serial number 5742), which was calibrated before and after the measurement session. Atmospheric conditions were clear and wind speed was light and variable during noise data collection and had little effect on sound propagation.



5. Model Input Data

TNM inputs were developed for the Project, including traffic volumes, classifications, speeds, roadway

geometry, receiver locations, and site acoustic properties. Traffic volume estimates and vehicle

classifications for the NM 599 on-ramp and US 84/285 mainline were obtained from Project-specific

NMDOT Traffic Volume Estimates (2019) for existing 2019 conditions and the future 2039 design year.

Traffic volumes on NM 599 were obtained from the NMDOT’s count station data for 2015 and

extrapolated to 2039, based on the forecasted growth rate on US 84/285. Traffic data used in the model

are shown in Table 3. Posted speed limits were used in the TNM model. To represent roadway and

receiver locations, an x-y-z coordinate system was established from the Project Plan and Profile Sheets

developed by Radian Engineering LLC (2019). The TNM model uses x, y, and z coordinates to spatially

represent roadway noise line sources, receivers, and features such as noise barriers or terrain lines that

abate noise over distance.

Table 3. Existing and future traffic volumes (vehicles per hour)

Road Description

2019 Existing Traffic Volumes 2039 Projected Traffic Volumes

Autos Medium Trucks

Heavy Trucks

Autos Medium Trucks

Heavy Trucks

WB/ NB

EB/ SB

WB/ NB

EB/ SB

WB/ NB

EB/ SB

WB/ NB

EB/ SB

WB/ NB

EB/ SB

WB/ NB

EB/ SB

NM 599-US 84/285 On-ramp

NA 414 NA 18 NA 28 NA 630 NA 36 NA 57

NM 599 630 630 28 28 42 42 959 959 55 55 87 87

US 84/285 1207 1207 69 69 96 96 1824 1824 130 130 205 205

Notes: EB=east bound; NB=north bound; SB=south bound; WB=west bound.

6. Traffic Noise Modeling: No-Build Scenario

The TNM model was initially used to evaluate the no-build scenario with 2019 existing and 2039 future

traffic volumes on the NM 599-US 84/285 on-ramp, US 84/285 mainline, and NM 599 with current lane

configurations. The 10 receivers described previously were included in the TNM model to represent

residential areas potentially affected by the Project. The standard height of a receiver in the TNM model

is 5 feet, the height of an average person’s ear. This height was used in the initial modeling to represent

ground levels locations in the affected residential areas. The traffic counts, classifications, speeds, and

other input data described in Section 5 were used in the model. The ground topography along the west

side of the NM 599 on-ramp and US 84/285 was included in the model as a terrain line, which acts as a

natural barrier and affects noise propagation from the roadway. The existing noise wall along US 84/285

and the concrete wall barrier in the center of US 84/285 were also modelled as barriers with TNM. The

two scenarios initially modeled included 2019 and 2039 traffic volumes with the current number of

lanes and geometric conditions. The results are shown in Table 4.



The model results in Table 4 show that noise levels would increase by an average of approximately 2.85

dBA between 2019 and 2039 with existing roadway geometry. The increase is the result of greater traffic

volumes, which are approximately 57-percent higher in 2039 than in 2019, and higher percentages of

heavy trucks, estimated to increase from 7-percent in 2019 to 9.52-percent in 2039 on US 84/285.

Typically, a 100-percent increase—or doubling—of traffic volumes results in a 3-dBA increase in sound

levels due to the logarithmic scale of the dBA units. Therefore, the 2.85-dBA average increase fits

reasonable expectations, with the increase in truck traffic between the 2019 and 2039 no-build

scenarios. A 3-dBA increase in sound that occurs over time is considered just barely perceptible to the

average person. None of the noise levels approach or exceed the NACs under 2019 or 2039 no-build

conditions.

Table 4. Existing and future no-build noise-modeling results (average A-weighted decibels [dBA Leq])

Receptor Number

Description

Noise Levels Difference

2019 No-Build

2039 No-Build

2039 – 2019 No-

Build

1 North Zocalo-250 feet to NM 599 and On-ramp 56.9 59.8 2.9


3 Zocalo - Avenida Rincon-650 to 1,100 feet to US 84/285 46.2 49.0 2.8

4 East side Zocalo-450 feet to US 84/285 45.9 48.6 2.7

5 East side Zocalo-Avenida Celaya-280 feet to US 84/285 50.5 53.3 2.8

6 East side Zocalo- Avenida Colima-70 feet to US 84/285 56.3 59.2 2.9

7 South Zocalo- Circulo de Morelia-125 feet to US 84/285 60.5 63.5 3.0

8 South Zocalo- Avenida Morelia-250 feet to US 84/285 57.7 60.7 3.0

9 Reserve at Santa Fe-380 feet to US 84/285 54.3 57.2 2.9

10 Viento Drive apartments-280 feet to US 84/285 59.3 62.0 2.7

7. Evaluation of Impacts: Build Scenario

Noise impacts occur when predicted noise levels approach or exceed 67 dBA at noise-sensitive locations

(Category B and C receptors), or when implementation of a roadway project results in a 10-dBA increase

over existing noise levels. To evaluate project impacts, the TNM model was used to compare the 2039

build scenario with the 2019 no-build noise levels (Table 5). The 2039 build scenario considered the

proposed geometric changes to the NM 599 on-ramp with other factors remaining the same. As shown

in Table 5, noise levels under the 2039 build scenario are essentially the same as the 2039 no-build

scenario. The minor changes are the result of numeric rounding in the model. The proposed relocation

of the on-ramp does not affect noise in the Project area.



Table 5. Future build noise modeling results (average A-weighted decibels [dBA Leq])

Receptor Number

Description


2019 No-Build

2039 Build

2039 Build – 2019 No-Build











Because many of the residential apartments and condominiums have second story, outdoor balconies,

an additional analysis was conducted of receivers at a height of 14 feet. Only the 2019 existing condition

and 2039 build scenario were analyzed since the 2039 no-build and build scenarios are very similar. The

results of the analysis in Table 6 show that noise increases slightly at the balcony level over the ground

level receivers. This occurs because there is less noise attenuation from surface terrain. At the 14-foot

height, none of the noise levels approach or exceed the NACs under 2019 or 2039 build conditions.

Table 6. Balcony Height: Future build noise modeling results (average A-weighted decibels [dBA Leq])

Receptor Number

Description


2019 No-Build

2039 Build

2039 Build – 2019 No-Build













8. Conclusions

State and federal noise policies require that when traffic noise impacts occur, noise abatement must be

considered and implemented if found to be feasible and reasonable (NMDOT 2011). The term “feasible”

indicates that noise-abatement measures will achieve at least a 5-dBA noise reduction at 50 percent of

the impacted receivers, and that it is possible to construct the abatement measures. The criteria for

“reasonableness” include consideration of the viewpoints of affected property owners and residents,

determination that the abatement measures are cost effective (i.e., cost less than $40,000 per benefited

receiver), and demonstration that a noise reduction of 7 dBA will be achieved at 10 percent of the

benefited receivers. Typically, noise abatement includes measures such as construction of noise barriers,

modification of horizontal or vertical geometric design features, or traffic management techniques such

as limitations on truck traffic. Because the analysis shows that noise impacts would not occur in the

Project area as a result of the proposed improvements, noise abatement measures are not justified and

were not considered further.

9. References

Federal Highway Administration (FHWA). 2004. Traffic Noise Model (Version 2.5): report no. FHWA-PD-

96-010.

FHWA. 2011. Highway traffic noise: analysis and abatement guidance. FHWA-HEP-10-025. December.

New Mexico Department of Transportation (NMDOT). 2011. Infrastructure Design Directive IDD-2011-

02: procedures for abatement of highway traffic noise and construction noise. April.

Radian Engineering LLC. 2019. Southbound On-Ramp from NM 599 to US 84/285-MP 165.5 to 166.5.

Preliminary 30% Plan Set: Plan and Profile Sheets.

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