SLIP20 - We are ready for sonROAD18

In summer 2023, the new noise calculation model sonROAD18 will be introduced in Switzerland. The new calculation model allows a more detailed noise calculation than the existing StL86+ model.

The engineering software SLIP 20 allows to perform noise calculations with the new model sonROAD18. We at G+P AG have tested the implementation of sonROAD18 in SLIP20 in many projects and are convinced that SLIP20 is ready for the new era of road noise calculation.

SLIP20 - We are ready for sonROAD18
SLIP20 - We are ready for sonROAD18
SLIP20 - We are ready for sonROAD18
SLIP20 - We are ready for sonROAD18
SLIP20 - We are ready for sonROAD18

SLIP - Software for noise prediction

SLIP is an engineering software that has established itself throughout Switzerland for the processing of project studies, cadastral work, acoustic dimensioning and economic assessment of noise protection measures and remediation planning.

SLIP is continuously adapted to the new and increasing demands of practice and the needs of the users. With the new version SLIP 20, the range of application and the functionality of the software have been further extended - in particular the new calculation model sonROAD18.

SLIP is available in German and in French.

System requirements: Windows ≥7, 64-bit; Intel/AMD x86-64 CPU, ≥2 cores; ≥4 GB RAM.



When implementing sonROAD18 in SLIP20, we attached great importance to making the changeover from road noise calculations with STL86+ to sonROAD18 as simple as possible for our users. To ensure that the familiar and proven SLIP workflow is not changed by the new calculation model, all auxiliary tools for the new model (SWISS10 converter, pavement interface) have been fully implemented.
Road noise calculations with the new calculation model are possible in all levels of detail: from calculations with traffic data from the existing projects (DTV, N2, v) to calculations based on detailed traffic surveys with SWISS10+ projects and spectral CPX results.

In order to enable environmental acousticians to quickly familiarise themselves with the features of the new model, we have added functions that allow a comparison between STL86+ and sonROAD18 with just a few additional clicks.

Versatile calculation options

The following calculation models are implemented in SLIP'20 (multicore):

  • Road noise: SonRoad18 (NEW), StL-86+ extended with reflections (IMPROVED) and tunnel portal;
  • Railway noise: SEMIBEL extended with reflections and tunnel portal;
  • Point and area sources: Frequency-dependent propagation according to ISO 9613 (IMPROVED).
  • Meteorological effects (NEW) can be considered in calculations based on ISO 9613 (incl. SonRoad18).


Editing large amounts of data

More and more detailed digital bases are available for noise calculations. This quickly results in projects with an enormously large amount of data. SLIP offers various auxiliary functions to process large amounts of data efficiently:

  • Simplification DTMNEW: High-resolution DTMs can be simplified in function to the road distance. Thanks to this function, the amount of data can be reduced by approx. 75% without any relevant loss of information.
  • Calculation algorithm (IMPROVED): Thanks to various optimisations (more usable RAM, multi-core processors) SLIP can optimally use the computing power of your PC.

DTM before simplification:

DGM vor der Vereinfachung - Lärmberechnung

DTM after simplification:


Interfaces to CAD and GIS

The import and export functions (IMPROVED) of SLIP 20 enable an efficient exchange of data with CAD and GIS:

  • Raster: TIFF, JPEG, PNG, BMP and a WMS interface.
  • Vector: SHAPE, QSI, DXF, KML (Google Earth and Google Maps), XYZ (DGM) and ESRI Grid.

Plan illustrations

SLIP 20 has many functionalities for creating plan views. For each plan view, legends, dimension bar, title block (for title pages), format and orientation can be selected and saved individually.

Convincing presentations in Google Earth can be easily created, which include immissions at receiver points and/or area representations.



Individual courses for newcomers and advanced users (e.g. how do I use sonROAD18 in SLIP20 correctly) can be organized and offered at short notice. We at Grolimund + Partner AG will be happy to advise you.


SLIP 20 can be ordered online ( or from Christoph Ammann (062 836 30 31,