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

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].

$L A e q = E + C_{o} + C_{r} - D_{a} - D_{l} - D_{b} - D_{m}$

$D_{l} = 0.01 \cdot d^{0.9}$

$D_{m} = \max (0.0, 3.5 \cdot (1.0 - e^{\frac{- 0.04 \cdot d}{h_{s} + 0.75 + h_{c} + 0.75}}))$

where:

L A e q

= equivalent noise level (dB(A))

E

= calculated emission

C_{o}

= acceleration term on intersections (default = 0 dB(A))

C_{r}

= reflection term. This term is not used, and by default 0 dB.

D_{a}

= distance reduction

D_{l}

= air reduction

D_{b}

= surface reduction. This term is not used, and by default 0 dB.

D_{m}

= calculated meteorological reduction

d

= distance from the receiver to the source.

e

= Euler's number, approximated as 2.7182.

h_{s}

= Building datum height (DTM) of the noise source

h_{c}

= 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:

$C_{o} = 1.4 + \frac{Q_{v} + Q_{t} + Q_{b}}{Q_{c} + Q_{v} + Q_{t} + Q_{b}}$

where:

Q_{c}

= number of cars per hour

Q_{v}

= number of vans per hour

Q_{t}

= number of trucks per hour

Q_{b}

= number of buses per hour

Distance reduction

Distance reduction is computed as:

$D_{a} = 10 \cdot l o g_{10} (r)$

where:

D_{a}

= distance reduction

r

= shortest distance between the source and point of evaluation

Emission

Emission is computed as:

$E = 10 \cdot l o g_{10} (1 0^{\frac{E c}{10}} + 1 0^{\frac{E v}{10}} + 1 0^{\frac{E t}{10}} + 1 0^{\frac{E b}{10}})$

where:

E

= the combined noise emission

E c

= the calculated noise emission for cars

E v

= the calculated noise emission for vans

E t

= the calculated noise emission for trucks

E b

= 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:

$E c = E_{c, s t a r t} + E_{c, m u l t} \cdot l o g_{10} (\frac{V_{c}}{V 0_{c}}) + 10 \cdot l o g_{10} (\frac{Q_{c}}{V_{c}}) + σ + τ \cdot l o g_{10} (\frac{V_{c}}{V 0_{c}})$

where:

E_{c, s t a r t}

Emission start value. Configurable with model attribute Emission start (Traffic Noise Overlay). See also: InfoMil [2]

E_{c, m u l t}

Emission factor. Configurable with model attribute Emission mult (Traffic Noise Overlay). See also: InfoMil [3]

V_{c}

= The traffic type's speed, configured in roads with attribute TRAFFIC_SPEED.

V 0_{c}

= The traffic type's reference speed, configured per traffic type using the model attribute V0.

Q_{c}

= 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.

References

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

[ref-srm1-1] Standard Calculation Method 1 (SRM1) ∙ Found at: http://wetten.overheid.nl/BWBR0031722/2015-07-01#BijlageIII

[1]

@@ Line 1: / Line 1: @@
-The calculations for the [[Traffic Noise Overlay]] follow the standard rekenmethode 1 (SRM 1){{ref|srm1}}.
+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>
@@ Line 25: / Line 25: @@
 ===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 followed:
+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(r)</math>
+<math>D_a = 10 \cdot log_{10}(r)</math>
 where:
@@ Line 38: / Line 44: @@
 : <math>r</math> = shortest distance between the source and point of evaluation
-[[File:Geluidsoverlast.png|600px]]
+[[File:Geluidsoverlast.png|600px|Traffic Noise.]]
 ===Emission===
 Emission is computed as:
@@ Line 51: / Line 58: @@
 :<math>Eb</math> = 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 followed for car traffic:
+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:
 <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>
@@ Line 58: / Line 65: @@
 :<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/]
 :<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 Function Value [[Traffic speed (Traffic Noise Overlay)|TRAFFIC_SPEED]].
+:<math>V_c</math> = The traffic type's speed, configured in roads with attribute [[Traffic speed (Traffic Noise Overlay)|TRAFFIC_SPEED]].
 :<math>V0_c</math> = The traffic type's reference speed, configured per traffic type using the model attribute [[V0 (Traffic Noise Overlay)|V0]].
-:<math>\sigma</math> = road surface correction value at reference traffic speed. Configurable in roads with Function Value [[Traffic noise sigma (Traffic Noise Overlay)|TRAFFIC_NOISE_SIGMA]]
+:<math>Q_c</math> = number of cars per hour, configured with Function Value [[Cars per hour (Function Value)]]
-:<math>\tau</math> = road surface correction factor per 10 km/hour deviation from reference traffic speed. Configurable in roads with Function Value [[Traffic noise tau (Traffic Noise Overlay)|TRAFFIC_NOISE_TAU]]
+:<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
 |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=
 * [[Traffic Noise Overlay]]

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

Latest revision as of 09:40, 15 July 2026

Contents

Acceleration term on intersections

Distance reduction

Emission

Notes

See also

References

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

Latest revision as of 09:40, 15 July 2026

Acceleration term on intersections

Distance reduction

Emission

Notes

See also

References

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