Traffic Noise Overlay

What is the Traffic Noise overlay?

Active Traffic Noise overlay

The Traffic Noise overlay is an Overlay which displays the impact of traffic noise in different colors for the project area. Based on traffic flow, distance and several computation parameters a grid is calculated for the project area. Note, this overlay only shows the impact of traffic noise on top of a background value of 48 dB(A). Influence of other sources (e.g. windmills, air traffic, factories, etc) is excluded.

Calculations

The calculations follow the standard rekenmethode 1 (SRM 1), as described on [1]:

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

where:

• LAeq: equivalent noise level (dB(A))
• E: emission
• Co: acceleration term (default = XXX dB(A))
• Cr: reflection term (omitted)
• Da: distance reduction
• Dl: air reduction (default = XXX dB(A))
• Db: surface reduction (default = XXX dB(A))
• Dm: meteorological reduction (default = XXX dB(A))

Default values are taken from InfoMil [2]

Emission

Emission is computed as:

E = 10 * log(10^(Elv/10)+10^(Emv/10)+10^(Ezv/10)

Per vehicle category, the emission is computed as:

Em = am + bm * log(m/v0) + 10 * log(Q/vm)+Cw;m

and

Cw;m = σm + τm x log(vm/v0,m)

where:

• m: vehicle category (light weihgt, medium weight and heavy)
• a and b: factors to be found at InfoMil [3]

• Cw = road surface correction
• 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:

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

[[File:Geluidsoverlast.png]|600px|left]]

Adding and removing

Adding and removing overlays is a generic process, however, certain overlays are dependent on other assets being present too, such as indicators, terrains, vacancy, images, etc. For more information please refer to the respective main articles for the specific overlays.

How to add the Traffic Noise overlay:

1. Select in the editor '3D World' from the ribbon
2. Select 'Overlays' > 'Edit overlays' from the ribbon bar
3. Select the Traffic Noise overlay from the drop down menu on the bottom of the left panel
4. Select 'Add' from the bottom of the left panel
5. The overlay icon will now appear under the mini map

• 

  1. Select 3D World

• SelectEditOverlay.jpg

  2. Select Overlays > Edit overlays

• SelectDropDown.jpg

  3. Select desired overlay from drop down menu on the bottom of the left panel

• 

  4. Select 'Add' from the bottom of the left panel

• OverlayIconPresent.jpg

  5. The overlay icon will now appear under the mini map

How to remove an overlay:

1. Select in the editor '3D World' from the ribbon
2. Select 'Overlays' > 'Edit overlays' from the ribbon bar
3. Select the desired overlay'*' from the list of active overlays'**' on the left panel
4. Select 'remove' from the bottom of the left panel
5. Confirm the removal in the pop up confirmation message

• 

  1. Select 3D World

• SelectEditOverlay.jpg

  2. Select Overlays > Edit overlays

• SelectOverlay.jpg

  3. Select desired overlay from the list of active overlays on the left panel

• 

  4. Select 'Remove' from the bottom of the left panel

• 

  5. Confirm the removal in the pop up confirmation message

Sometimes it can be convenient to duplicate an already existing overlay. To do so, follow the steps for removal, but select 'Duplicate' in stead of 'Remove'.

References

The overlay calculations are based on Standard Calculation Method 1 (SRM1) as defined by the dutch government: wetten.overheid.nl