EU-Noise Mapping

The European Noise Directive ( http://europa.eu.int/en/record/green/gp9611/noise.htm) uses the noise descriptor L_den, the day, evening, and night average noise level. The noise levels in the evening time slot are raised 5 dB and in the night time slot 10 dB. Then the time average is taken for all 24 hours. Aside from the L_den the L_night is also used to determine the noise quality in an area.

The new concepts create challenges for noise modeling programs. Most of the existing standards used in Europe do not have the three time slots. These three time slots must be localized so the definition of the evening time can be different in Finland tan it is in Spain.  Data is often not available on an hourly basis for all 24 hours. Because the noise mapping is supposed to be repeated at regular intervals, the traffic volume must be updated in an existing model. For countries without their own regulations, a default suite of standards was designated consisting of the French NMPB for road, the Dutch RMR 2002 for rail, the ISO 9613 for industry and ECAC for aircraft noise.

SoundPLAN 6.1 provided answers to all these challenges!

The time slots can be user defined so the start of the evening time is flexible. 

The data supply to calculate the emission is flexible and works with the concepts of templates where some roads have the exact traffic volume for each of the 24 hours of the day from traffic detectors in the road. With the templates selected for comparable roads, the real traffic load is extrapolated for each segment of each road where the average daily traffic changes.

The traffic volume templates are hosted in a library the user controls. He can choose to have the measured 24 hour numbers for each road or use templates for similar roads to extrapolate the volume for each time slot.

 For each standard ,the user chooses if the original time slots shall be used or the extended L_den based values. The L_den based entry is tied to the traffic templates, so any time slot configuration can be simulated. In the case of the UK Calculation of Road Traffic Noise, the decision also changes the descriptor from the L₁₀ to the L_eq.

In the Geo-Database, there are various choices for data input because different projects have different data available. SoundPLAN can use many combinations and formats of the traffic volume information. In the picture above, the emission levels are calculated from the average daily traffic volume for cars and trucks distributing the vehicles into the 3 time slots using a traffic volume template.

To update the traffic volume for the periodical updates of the noise maps, SoundPLAN recommends importing the traffic volume into a separate layer of objects. The data will probably be provided in a tabular format with a line in a spreadsheet (link) representing the traffic from one node to a second node. With a database key, the links are tied into the emission level calculation. To update the traffic volume and recalculate the emission for an entire road network, the only thing the user must do is import a new traffic file and hit the update button to recalculate the emission values.

 The section ID is the database key and needs to be present in the section definition of the road and the abstract traffic data file.

In the standard selection box, the user can define the emission level required for the project (L_den versus native L_???)

All standards the European Noise Mapping requires are already implemented and tested in SoundPLAN.

With SoundPLAN 6.1 onward, even calculating the biggest noise map is possible using the Distributed Computing (DC) module. DC automatically distributes the computation intensive calculations on a TCP/IP based network. There is no limit to the number of PCs that can be harnessed for calculating noise maps.

Last modification: 24 November 2003