Traffic noise formula (Traffic Noise Overlay): Difference between revisions

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The calculations for the [[Traffic Noise Overlay]] follow the standard rekenmethode 1 (SRM 1), as described on http://wetten.overheid.nl/BWBR0031722/2015-07-01#BijlageIII:
The calculations for the [[Traffic Noise Overlay]] follow the standard Calculation Method 1 (SRM 1){{ref|srm1}}.
 
<math>LAeq = E + C_o + C_r - D_a - D_l - D_b - D_m</math>
 
<math>D_l = 0.01 \cdot d^{0.9}</math>
 
<math>D_m = \max( 0.0, 3.5 \cdot (1.0 - e^{ \frac{-0.04 \cdot d}{h_s + 0.75 + h_c + 0.75} }))</math>


LAeq = E + Co + Cr - Da - Dl - Db - Dm


where:
where:
* LAeq: equivalent noise level (dB(A))
: <math>LAeq</math> = equivalent noise level (dB(A))
* E: emission
: <math>E</math> =  [[Traffic noise formula (Traffic Noise Overlay)#Emission|calculated emission]]
* Co: acceleration term (default = XXX dB(A))
: <math>C_o</math> = [[Traffic noise formula (Traffic Noise Overlay)#acceleration term on intersections|acceleration term on intersections]] (default = 0 dB(A))
* Cr: reflection term (omitted)
: <math>C_r</math> = reflection term. This term is not used, and by default 0 dB.
* Da: distance reduction
: <math>D_a</math> = [[Traffic noise formula (Traffic Noise Overlay)#Distance reduction|distance reduction]]
* Dl: air reduction (default = XXX dB(A))
: <math>D_l</math> = air reduction
* Db: surface reduction (default = XXX dB(A))
: <math>D_b</math> = surface reduction. This term is not used, and by default 0 dB.
* Dm: meteorological reduction (default = XXX dB(A))
: <math>D_m</math> = calculated meteorological reduction
: <math>d</math> = distance from the receiver to the source.
: <math>e</math> = Euler's number, approximated as 2.7182.
: <math>h_s</math> = Building datum height (DTM) of the noise source
: <math>h_c</math> = Building datum height (DTM) of the noise receiving cell.


Default values are taken from InfoMil [https://www.infomil.nl/onderwerpen/geluid/regelgeving/wet-geluidhinder/wegverkeerslawaai/akoestisch-rapport/cwegdek/]
Default values are taken from InfoMil [https://www.infomil.nl/onderwerpen/geluid/regelgeving/wet-geluidhinder/wegverkeerslawaai/akoestisch-rapport/cwegdek/]
===Acceleration term on intersections===
Accelerating on intersections can cause more noise. This value is only calculated for roads of category INTERSECTION. It is calculated as follows:
<math>C_o = 1.4 + \frac{Q_v + Q_t + Q_b}{ Q_c + Q_v  + Q_t + Q_b}</math>
where:
: <math>Q_c</math> = number of cars per hour
: <math>Q_v</math> = number of vans per hour
: <math>Q_t</math> = number of trucks per hour
: <math>Q_b</math> = number of buses per hour
===Distance reduction===
Distance reduction is computed as:
<math>D_a = 10 \cdot log_{10}(r)</math>
where:
: <math>D_a</math> = distance reduction
: <math>r</math> = shortest distance between the source and point of evaluation
[[File:Geluidsoverlast.png|600px|Traffic Noise.]]


===Emission===
===Emission===
Emission is computed as:
Emission is computed as:


<math>E = 10 \cdot log_{10}(10^{\frac{Ec}{10}} + 10^{\frac{Ev}{10}} + 10^{\frac{Et}{10}} + 10^{\frac{Eb}{10}})</math>
<math>E = 10 \cdot log_{10}(10^{ \frac{Ec}{10} } + 10^{ \frac{Ev}{10} } + 10^{ \frac{Et}{10} } + 10^{ \frac{Eb}{10} })</math>
 
The emission per type of traffic is computed as follow:
 
Car:
<math>Ec = E_{c,start} + E_{c,mult} \cdot log_{10}(\frac {V_c}{V0_c}) + 10 \cdot log_{10}(\frac{Q_c}{V_c}) + \sigma + \tau \cdot log_{10}(\frac{V_c}{V0_c})


where:
where:
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:<math>Eb</math> = the calculated noise emission for buses
:<math>Eb</math> = the calculated noise emission for buses


* m: vehicle category (light weihgt, medium weight and heavy)
The emission per type of traffic is computed similarly, with values specific to the type of traffic. It is calculated as follows for car traffic:
* a and b: factors to be found at InfoMil [https://www.infomil.nl/onderwerpen/geluid/regelgeving/wet-geluidhinder/wegverkeerslawaai/akoestisch-rapport/cwegdek/]


* Cw = road surface correction
<math>Ec = E_{c,start} + E_{c,mult} \cdot log_{10}( \frac {V_c}{V0_c} ) + 10 \cdot log_{10}( \frac{Q_c}{V_c} ) + \sigma + \tau \cdot log_{10}( \frac{V_c}{V0_c} )</math>
* σ = correction factor at reference traffic speed
* τ = correction factor per 10 km/hour deviation from reference traffic speed
 
===Distance reduction===
Distance reduction is computed as:
 
Da = 10 * log(r)


where:
where:
* Da: distance reduction
:<math>E_{c,start}</math> Emission start value. Configurable with model attribute [[Emission start (Traffic Noise Overlay)]]. See also: InfoMil [https://www.infomil.nl/onderwerpen/geluid/regelgeving/wet-geluidhinder/wegverkeerslawaai/akoestisch-rapport/cwegdek/]
* r: shortest distance between the source and point of evaluation
:<math>E_{c,mult}</math> Emission factor. Configurable with model attribute [[Emission mult (Traffic Noise Overlay)]]. See also: InfoMil [https://www.infomil.nl/onderwerpen/geluid/regelgeving/wet-geluidhinder/wegverkeerslawaai/akoestisch-rapport/cwegdek/]
 
:<math>V_c</math> = The traffic type's speed, configured in roads with attribute [[Traffic speed (Traffic Noise Overlay)|TRAFFIC_SPEED]].
[[File:Geluidsoverlast.png|600px]]
:<math>V0_c</math> = The traffic type's reference speed, configured per traffic type using the model attribute [[V0 (Traffic Noise Overlay)|V0]].
 
:<math>Q_c</math> = number of cars per hour, configured with Function Value [[Cars per hour (Function Value)]]
:<math>\sigma</math> = road surface correction value at reference traffic speed. Configurable in roads with attribute [[Traffic noise sigma (Traffic Noise Overlay)|TRAFFIC_NOISE_SIGMA]]
:<math>\tau</math> = road surface correction factor per 10 km/hour deviation from reference traffic speed. Configurable in roads with attribute [[Traffic noise tau (Traffic Noise Overlay)|TRAFFIC_NOISE_TAU]]


{{article end
{{article end
|notes=
|notes=
* If the traffic amount is defined as a single value, that value is used for all defined [[Hours (Traffic Density Overlay)|hours]]. However, if the amount if an [[Attribute array|array of values]], each of the 24 indexes of that array are assumed to correspond to the hour denoted by those indexes, and as such that specific value from the array is used.
* If traffic amount is a single value, it applies to all defined [[Hours (Traffic Density Overlay)|hours]]. If it is an [[Attribute array|array of values]], each index corresponds to its respective hour.
|seealso=
|seealso=
* [[Traffic Noise Overlay]]
* [[Traffic Noise Overlay]]
|references=
|references=
* The overlay calculations are based on Standard Calculation Method 1 (SRM1) as defined by the dutch government: http://wetten.overheid.nl/BWBR0031722/2015-07-01#BijlageIII
<references>
{{ref|srm1
  |name=Standard Calculation Method 1 (SRM1)
  |author=
  |page=
  |source=
  |link=http://wetten.overheid.nl/BWBR0031722/2015-07-01#BijlageIII
  |lastvisit=
}}
</references>
}}
}}

Latest revision as of 09:40, 15 July 2026

The calculations for the Traffic Noise Overlay follow the standard Calculation Method 1 (SRM 1)[1].

LAeq=E+Co+CrDaDlDbDm

Dl=0.01d0.9

Dm=max(0.0,3.5(1.0e0.04dhs+0.75+hc+0.75))


where:

LAeq = equivalent noise level (dB(A))
E = calculated emission
Co = acceleration term on intersections (default = 0 dB(A))
Cr = reflection term. This term is not used, and by default 0 dB.
Da = distance reduction
Dl = air reduction
Db = surface reduction. This term is not used, and by default 0 dB.
Dm = calculated meteorological reduction
d = distance from the receiver to the source.
e = Euler's number, approximated as 2.7182.
hs = Building datum height (DTM) of the noise source
hc = Building datum height (DTM) of the noise receiving cell.

Default values are taken from InfoMil [1]

Acceleration term on intersections

Accelerating on intersections can cause more noise. This value is only calculated for roads of category INTERSECTION. It is calculated as follows:

Co=1.4+Qv+Qt+QbQc+Qv+Qt+Qb

where:

Qc = number of cars per hour
Qv = number of vans per hour
Qt = number of trucks per hour
Qb = number of buses per hour

Distance reduction

Distance reduction is computed as:

Da=10log10(r)

where:

Da = distance reduction
r = shortest distance between the source and point of evaluation

Traffic Noise.

Emission

Emission is computed as:

E=10log10(10Ec10+10Ev10+10Et10+10Eb10)

where:

E = the combined noise emission
Ec = the calculated noise emission for cars
Ev = the calculated noise emission for vans
Et = the calculated noise emission for trucks
Eb = the calculated noise emission for buses

The emission per type of traffic is computed similarly, with values specific to the type of traffic. It is calculated as follows for car traffic:

Ec=Ec,start+Ec,multlog10(VcV0c)+10log10(QcVc)+σ+τlog10(VcV0c)

where:

Ec,start Emission start value. Configurable with model attribute Emission start (Traffic Noise Overlay). See also: InfoMil [2]
Ec,mult Emission factor. Configurable with model attribute Emission mult (Traffic Noise Overlay). See also: InfoMil [3]
Vc = The traffic type's speed, configured in roads with attribute TRAFFIC_SPEED.
V0c = The traffic type's reference speed, configured per traffic type using the model attribute V0.
Qc = number of cars per hour, configured with Function Value Cars per hour (Function Value)
σ = road surface correction value at reference traffic speed. Configurable in roads with attribute TRAFFIC_NOISE_SIGMA
τ = road surface correction factor per 10 km/hour deviation from reference traffic speed. Configurable in roads with attribute TRAFFIC_NOISE_TAU

Notes

  • If traffic amount is a single value, it applies to all defined hours. If it is an array of values, each index corresponds to its respective hour.

See also

References

  1. Standard Calculation Method 1 (SRM1) ∙ Found at: http://wetten.overheid.nl/BWBR0031722/2015-07-01#BijlageIII