Overview of TNM

and Case Studies with TNM 2.5

By By

Panos D. Prevedouros, PhD

Department of Civil and Environmental Engineering

University of Hawaii at Manoa

June 2011

Outline

� TNM Fundamentals

� Data Input

� Data Preparation � Data Preparation

� TNM Sensitivity Case Studies

� TNM Case Studies on H-1 Freeway

2

What is TNM?

�State-of-the-art computer program for predicting noise levels

near a highway

�Uses a nationally representative noise emission database

� Emissions levels of 6,000 different vehicles under different � Emissions levels of 6,000 different vehicles under different

operating conditions

� Reference distance of 50 ft.

� Shielding effect of barriers, berms, grounds, buildings and

trees

4

History

� Before TNM, FHWA-RD-77-108 was in use for over 20

years

• No data for vehicles on grade or vehicles subject to

interrupted-flow conditions

� March 1998: FHWA released the Traffic Noise Model,

Version 1.0Version 1.0

• Version 1.0a, March 1999

• Version 1.0b, August 1999

• Version 1.1, September 2000

• Version 2.0, June 2002

• Version 2.1, March 2003

• Version 2.5, April 2004

• Version 3.0, September 2011

5

Basic Calculation ProcedureTNM computes the predicted noise levels through a series of

adjustments to the reference sound levels

1 ( )Aeq h traff i d siL EL A A A= + + +

• Max. sound level emitted by a vehicle /10 /10 /10( ) (0.6214 ) 10 10A B CA i iE s s= +

6

• Max. sound level emitted by a vehicle passing by at a distance of 50 ft.

• Adjustment for the traffic volume• Adjustment for the distance and

roadway length

• Adjustment for shielding

A i i

10( )

10 13.2iitraff i

VA X Log dB

S = −

( )( )10 1510 180dA X Log dBd α =

( )12SAvg SL SRϕ ϕ ϕ= +

TNM Applications

� Calculate noise levels at receiver locations for both

conditions: Existing and future

� Design highway noise barriers

� Communicate predicted noise results from proposed new

projects to local authorities and general public

� Develop noise contours

� Required for federally funded highway projects

7

Noise Analysis

� Input Files

� Model Building

� Data Input

� Data Check� Data Check

� Results

8

Input Parameters� Main basic parameters:

� Temperature: 68 F � 80 F

� Relative humidity: 50% � 80%

� Pavement type: Average

� Modeling parameters

2. Length, width and types:

• Road segments

• Shoulders

• Medians

3. Topographical and shielding 1. Traffic volume / speed / class:

� Autos (2 axles and 4 tires)

� Heavy trucks (3 or more axles and 6 or

more tires)

� Medium trucks (2 axles and 6 tires)

� Buses (2 or 3 axles and 6 or more

tires)

� Motorcycles (2 or 3 tires)

10

3. Topographical and shielding

features:

• Existing berms

• Walls

• Tree zones

• Building rows

4. Receiver locations

Methodology

� TNM steps

� Identification of existing

land use categories within

500 ft.

� Data collection

� Segmentation of highway

� Receiver selection

� Model development

� Simulation

� Impact analysis

11

Noise Levels for Various

Conditions (1/4)

Determinants Change by Results in noise

levels Reference Remarks

±12% ±0.6 dBA [43]

±9% ±0.4 dBA [43]

Test was done in a multilane highway ( 3-

lane in each direction), slightly rolling

terrain and short grass ground in between

receivers and highway. Vehicles speed

was 65 mph.

12

20% 1 dBA

100% 3 dBA

1% Medium truck 0.1 dBA

1% Heavy truck 0.2 - 0.3 dBA

1% Motorcycle 0.2 dBA

1% Bus 0.1 dBA

Vehicle speed ±12% ±1 dBA [13,43]

Test was done in a multilane highway ( 3-

lane in each direction), slightly rolling

terrain and short grass ground in between

receivers and highway. Vehicle speed was

65 mph.

Increase in volume

Increase vehicle volume on each category

[22]Vehicle volume

[22]

Not

From See slide no. 61 for reference citations

Noise Levels for Various

Conditions (2/4)

- 4 dBA Receiver at 100 ft. away

- 7 dBA Receiver at 300 ft. away

- 11 dBA Receiver at 700 ft. away

0.7 dBA Receiver at 100 ft. away

1.5 dBA Receiver at 300 ft. away [22]

Change in ground

surface with out

barrier, building

Hard surface to lawn

Hard surface to pavement

Determinants Change by Results in noise

levels Reference Remarks

13

1.5 dBA Receiver at 300 ft. away

0.5 dBA Receiver at 100 ft. away

0.7 dBA Receiver at 300 ft. away

Field grass, lawn and loose

soil from one to other

No significant

difference For receivers located from 100 to 500 ft.

Paved to hard surface - 2 dBA

Paved to loose surface - 2 dBA

Paved to lawn surface - 9 dBA

Paved to field grass surface - 9 dBA

[22]barrier, building

rows, terrain lines in

the highway of 25 ft.

width

Study on Pima Hwy.

Florida[39]

Receivers at 500 ft. away from the road

edge

Hard surface to pavement

Hard surface to water

Not

From

Noise Levels for Various

Conditions (3/4)

Temperature 30°F - 70°F Increase by

Noise Levels for Various

Conditions (4/4)10 to 20 m - 3.1 dBA

20 to 30 m - 1.7 dBA

30 to 40 m - 1.3 dBA

40 to 50 m - 1 dBA

50 to 60 m - 0.9 dBA

90 to 100 m - 0.6 dBA

100 to 110 m - 0.5 dBA

110 to 120 m - 0.5 dBA

120 to 130 m - 0.4 dBA

For vehicles running at 100 km/hr and

hard ground surface [50]

Changing receiver

position from road

edge

15

120 to 130 m - 0.4 dBA

130 to 140 m - 0.4 dBA

140 to 150 m - .4 dBA

Gaps are less than 10% of

length

Depend on height

of the building [41] Work like a barrier

20 to 30% - 5 dBA to - 7 dBA [35, 41]

40 - 50% - 2 dBA [22] 25 ft. high

≥50% - 3 or more dBA [22, 35, 41]

- 3.2 dBA For receiver 20 m away from road edge

- 2.8 dBA For receiver 30 m away from road edge

- 2.9 dBA For receiver 40 m away from road edge

Grade change 3% 0.01 dBA [60]

Barrier height [50]2 to 3 m

Gaps of building row

Not

From

Homogeneous Segments

�Freeway is divided into segments based on

large changes to major TNM inputs

�Segments are considered homogeneous as

long as the changes on noise levels are ±3

dBA compared to base case

16

Not

From

Suggested Criteria for

Homogeneous Segments Determinants Situation Limiting Value /Condition Effect on Noise Levels

Hard Should be same throughout the segment Same

Field grass, lawn and

loose soil Can change from one to another Not significant change

Vehicle volume Change ±20% ±1 dBA

Ground surface

17

Vehicle speed Change ±15% ±1 dBA

Freeway width or

number of lanes No change Should be same throughout segment (s) Same

Topographical

features No change

The average height of existing wall and

berms should be sameSame

Freeway grade Change ±3% Not significant change

Heavy trucks Change 3% 0.6 to 0.9 dBA

Not

From

Start from a central segment and expand on both directions as long as volume, speed, grade, and % HV fluctuate within these criteria values and there is no change in shielding. Viaducts, tunnels and high volume ramps are typical locations for ending a segment and starting a new one.

Sample Interface

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Required

Input Files

� Acquire scale map of

the highway and its

surroundings (500 ft.

swath)swath)

� Create DXF file in

AutoCAD with TNM

elements in the same

scale as the map

19

Model Building

� General information

• Units of length of

TNM elementsTNM elements

• Relative Humidity

• Temperature

• Ground Type

20

Importing and Digitizing DXF file

� Import DXF file from

AutoCAD

� Digitize TNM elements like

road, receivers, barriers etc.

� Many improvements in TNM � Many improvements in TNM

3.0

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Roadways � General information

• Width

• Pavement

• Grade

� Traffic flow

• Types, Volume and Speed • Types, Volume and Speed

� Traffic control

• Stop, Signal, Toll, On/off-ramp

22

Receivers

� General information• Name• Height• No of dwelling units• Locations • Locations

� Noise level criteria• Existing level• Noise reduction goal• Impact criteria level• Substantial increase

� Adjustment factors

23

Barriers

� General information

• Name

• Type• Type

• Height

• Perturbations

� Unit cost and

additional cost

24

Contours

� Set up contour

parameters

� Select contour zones

� Calculate sound level � Calculate sound level

contours

25

Other Inputs

� Building Rows

� Terrain Lines

� Ground Zones

� Tree Zones � Tree Zones

26

Data Check

� TNM checks for invalid inputs• Section with zero length • Vehicle with zero speed• Receiver position too close to

road

• Receivers with identical • Receivers with identical location

• Perturbation beyond max. or min. limit of barrier height

• Berms on structures • Grade of road >20%

27

Outputs

� Sound level results

� Barrier design and

cost

� Sound level contours

28

TNM Sensitivity

� Case Study I

H-1 Fwy. section between Wilder Ave. and Punahou St.

� Case Study II� Case Study II

H-1 Fwy. Kahala Mall Viaduct (Ainakoa Ave. to 20th Ave.)

� Case Study III

Likelike Hwy. between School St. and Emmeline Pl.

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Case Study I

Objective was to determine the effect of:

• Noise from freeway only

• Noise from frontage roads and on-ramp

• Noise level with a reduction of traffic volume• Noise level with a reduction of traffic volume

• Noise level with noise barrier on one side only

• Noise level if the receiver locations are moved

10 ft. or 50 ft. further away from the freeway

31

Results

� Traffic noise is mainly from freeway

Receivers

1e

Name 10ft shift 50ft shift 10ft shift 50ft shift

RNF11 78.8 78.8 78.3 46.3 78.2 74.7 65.7 65.7 65.3 66.3 63.9 63.8 63.9 63.4 62.0 62.1 61.7

RNF12 76.3 76.4 75.9 55.1 75.9 71.8 65.5 70.0 69.5 69.9 66.8 64.3 69.7 69.2 62.8 69.4 68.9

RNF13 79.9 79.9 79.4 53.7 79.0 75.5 65.7 65.9 65.4 67.0 64.9 64.2 64.3 63.8 62.2 62.2 61.7

RSF11 76.5 76.5 76.0 60.6 76.0 72.5 65.3 65.9 65.4 65.5 62.7 64.0 64.8 64.3 62.4 63.5 63.0

RSF12 76.2 76.2 75.7 59.1 75.8 72.5 65.3 65.8 65.3 65.5 62.7 64.0 64.6 64.1 62.4 63.3 62.8

RSF13 77.6 77.7 77.2 62.8 77.1 73.8 66.0 67.6 67.1 67.1 64.5 64.7 66.6 66.1 62.9 65.5 65.0

1b

10 ft height barrier 12 ft height barrier 15 ft height barrier

North

Side

South

Side

1e

1a 1b 1c 1c 1a 1b 1c

No Barrier

1d 1a 1b 1c 1a

� Traffic noise is mainly from freeway

� Noise level does not change when barrier is installed on

one side only

� Noise level is not reduced with 10% decrease in traffic

� Small errors in precision in location of receivers do not

change the results dramatically (~10 ft or so)

� A 10 ft. relocation has imperceptible improvement < 1 dBA

� A 50 ft. relocation has perceptible improvement > 3 dBA

32

Case Study II

Objective was to determine the effect of:

• Freeway viaduct on noise level to receivers

Four scenarios were analyzed:

• AM peak hour noise without noise barriers• AM peak hour noise without noise barriers• AM peak peak hour noise with 10 ft. noise barriers• Evening noise without noise barriers• Evening noise with 10 ft. noise barriers

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ResultsE x is t i n g l e v e l C r t . 1 C rt . 2

R e c e i v e r N o B a rr ie r 1 0 fe e t N o B a rr ie r 1 0 fe e t L e s s th a n 6 6 d B A

L e s s th a n 6 6

d B A

O v e r 8 d B A

re d u c t i o n

R 1 5 8 . 8 5 5 . 2 5 2 . 1 5 0 .0 O k O k N o

R 2 5 6 . 4 5 3 . 0 5 1 . 7 5 0 .1 O k O k N o

R 3 5 7 . 1 5 4 . 7 5 0 . 8 4 9 .1 O k O k N o

R 4 5 8 . 2 5 5 . 0 5 3 . 5 5 1 .5 O k O k N o

R 5 5 7 . 9 5 5 . 5 5 1 . 5 5 0 .0 O k O k N o

R 6 5 5 . 7 5 3 . 0 5 1 . 0 5 0 .2 O k O k N o

R 7 6 8 . 2 6 5 . 0 6 2 . 7 6 2 .5 N o O k N o

R 8 7 2 . 3 7 2 . 3 6 6 . 6 6 7 .6 N o N o N o

R 9 7 2 . 3 6 2 . 1 6 7 . 5 5 7 .5 N o O k Y e s

1 0 f t B a rr ie r

N i g h t M o r n i n g P e a k H o u r

N o i s e l e v e l

With out

barrier

With 10ft

barrier

With out

barrier

With 10ft

barrier

R7 65.0 farther away from the Hwy 68.2 65.0 62.7 62.5

R8 65.0 first row 72.3 72.3 66.6 67.6

R9 32.0 first row 72.3 62.1 67.5 57.5

Morning peak

Noise level in dBA

ReceiversHeight from road level in meters

Locations of receivers Night 10 -11 PM

R 9 7 2 . 3 6 2 . 1 6 7 . 5 5 7 .5 N o O k Y e s

34

� Noise from the freeway viaduct affects the high-rise

apartment buildings more significantly than low-rise

buildings

� Noise barriers are not effective for mitigating noise

levels for high-rise buildingslevels for high-rise buildings

� Effect of highway noise during night time is less than

morning peak hour (but annoyance is a separate issue)

35

Case Study III

Objective was to determine

the noise level sensitivity to:

• Relative Humidity

• Temperature

• Ground Type

• Grade of Road

36

Different Scenarios

37

Results

Items Change in ParametersChange in Noise Level in

Avg. in dBA

Change in

Temperature 85 to 65°F 0.13

Change in

Re lative Humidity 80 to 60 % 0.01

Change in Lawn to Water 2.27

Change in Ground Nature

Lawn to Water 2.27

Change in Road Grade

3% to Leve l -0 .01

38

References13. Illingworth and Rodkin, Inc., I- 80 Davis OGAC Pavement Noise Study. California

DOT, 2005.

22. Michael, H., Cerjan, J., Leasure, J., Evaluation of the FHWA traffic noise model for

highway traffic prediction. Colorado DOT. 2006.

35. Arnold, L.B., Highway Noise Study Analysis. Virginia DOT, 2001.

39. Pima Freeway Authority, Background and Sound Propagation, Pima Freeway,

Florida, 2005.Florida, 2005.

41. Miller, H., Freeway Noise Barrier Feasibility Study Final Report. District of

Columbia Government. 2001.

43. Nadella, S., Accuracy of a Traffic Noise Model Using Data from Machine Vision

Technology, Transportation Research Record, No 1941, 2005.

50. US DOT Research and Special Programs Administration John A, Volpe National

Transportation Systems Center, TNM, U.S. DOT, 2004.

60. Prevedouros, P.D., Li, Shenghong, and KC, Laxman, Tutorial and Case Studies on

TNM, University of Hawaii at Manoa, May 2009.

39

pdp@hawaii.edu

Thanks!