Road and railway traffic noise exposure (sonBASE 2021)
The noise data come from sonBASE, the nationwide noise calculation model of the Federal Office for the Environment (FOEN), for the reference year 2021. They cover exposure to road and railway traffic noise at façade points, buildings and dwellings, the assessment under the Noise Abatement Ordinance (NAO), the noise emissions and traffic volumes of the road network, and the number of people affected by noise per agglomeration.
For road traffic the calculations are based on the traffic figures of the national passenger transport model (NPVM 2021); for railway traffic on the 2021 emission cadastre (EK 2021). The data serve exclusively as statistical information at national and regional level and are not legally binding. Binding information on noise exposure and noise abatement is provided by the enforcement authorities: the Federal Roads Office (FEDRO) for national roads, the cantons for main and other roads, and the Federal Office of Transport (FOT) for railway traffic.
Results are returned in no particular order, and a single query is
limited to 10 000 rows. Queries that exceed the limit are rejected, not
truncated. Larger datasets are retrieved by splitting them into smaller
filter windows — for example by municipalityBfsNumber or limitValueClass
— and iterating. See Getting started → Pagination and limits
for details.
Road and railway traffic noise exposure
Eleven datasets describe the noise exposure at buildings. The façade points carry the values per point; buildings and dwellings carry the highest value occurring at the façade per object; the rating points show the dominant point per building or dwelling with the rating level and the limit value class under the NAO.
| Dataset | Content | Query |
|---|---|---|
| Façade points | About 36 million 3D points with the equivalent continuous sound levels (Leq) per period, the rating levels (Lr) for day and night and the partial levels by road owner (municipality, canton, national road). | noise.immissions.facade_point_immissions |
| Buildings | Per building the highest exposure (Leq) occurring at the façade per period, with the 2D footprint and information from the Federal Register of Buildings and Dwellings (RBD). | noise.immissions.building_immissions |
| Road noise rating level day / night (building rating point) | Rating level (Lr) at the dominant point of every building with residential or mixed use. | noise.immissions.road_day_building_rating_points, road_night_… |
| Railway noise rating level day / night (building rating point) | As above, for railway noise. | noise.immissions.rail_day_building_rating_points, rail_night_… |
| Dwellings | Per dwelling the highest exposure (Leq) occurring at the façade per period, with the 2D storey footprint and information from the RBD. | noise.immissions.dwelling_immissions |
| Road noise rating level day / night (dwelling rating point) | Rating level (Lr) at the dominant point of every dwelling. | noise.immissions.road_day_dwelling_rating_points, road_night_… |
| Railway noise rating level day / night (dwelling rating point) | As above, for railway noise. | noise.immissions.rail_day_dwelling_rating_points, rail_night_… |
The dominant façade point is the point on the building or dwelling with the highest exceedance of the limit value, given the immission level, the noise sensitivity level (ES) and the use. Dwellings are assigned to a storey, but their exact position (facing the road or away from it) is not known; every dwelling on a storey is therefore assigned the same highest level. Dwellings extending over several storeys may be exceptions.
Noise emissions and traffic volumes
The dataset Noise emissions and traffic volumes in road traffic (road
sections) contains the calculated noise emissions (Lre for day and night)
and the underlying traffic volumes for the Swiss road network (about
45 000 km). It is based on the emission model sonROAD18 and includes
parameters such as the signposted speed, the traffic volume by vehicle
category (Swiss10), the road surface and the gradient. The traffic data were
derived from the NPVM of the Federal Office for Spatial Development (ARE).
Query: noise.road_emissions.road_sections.
Analysis of people affected by noise
The dataset Agglomeration analysis of people affected by noise gives,
for the agglomerations of the FSO spatial classification 2020, the number of
people and dwellings affected by exceedances of the immission limit value
(ILV) from road and railway noise — by noise source and for day (06-22),
night (22-06) and day/night. For day/night, a person affected both by day and
by night is counted once. It is based on the permanent resident population
and the number of dwellings from the FSO Buildings and Dwellings Statistics
(GWS) 2021. Query: noise.agglomeration.exposure.
The label, unit and description of every column are available in the generic download and in the GraphQL schema.
Content and coverage
- Spatial: all of Switzerland. A road network of about 47 000 km is included, and of the about 5800 km of track under federal supervision about 4165 km (networks of SBB, BLS, SOB, SZU, Zentralbahn and RhB).
- Temporal: reference year 2021.
- Updates: periodically, every five years. A new edition replaces the existing datasets in full.
- Granularity: about 36 million 3D façade points for storey-level statements; buildings and dwellings, uniquely identifiable by the federal building and dwelling identifiers (EGID, EWID); over 600 000 road sections; agglomerations of the FSO spatial classification 2020.
Methodology
- Road traffic: traffic data of the NPVM 2021, calibrated against about 4000 counting stations and distributed to the Swiss10 vehicle categories with the Swiss10 converter. Emissions from the sonROAD18 model, propagation according to ISO 9613-2.
- Railway traffic: emissions from the FOT 2021 emission cadastre (calculated with sonRAIL), propagation with the Semibel model.
- 3D modelling: noise sources and buildings are modelled in 3D, based on swissTLM3D (road and rail geometries) and swissBUILDINGS3D 2.0 (building heights and roof shapes).
- Buildings: footprints and EGID come from the official cadastral survey. Buildings without an official EGID carry an artificial, mostly negative identifier.
- People affected: all people in a building are assessed by the loudest determination point. If it lies above the relevant limit value, all people in the building count as affected.
Quality and limitations
- The results support statements over medium to large areas. They are not suitable for local questions, since noise exposure may be over- or underestimated. No direct exposure of individual plots or buildings can be derived from them.
- For statistical analyses a threshold of 40 dB(A) is recommended. Below it, levels tend to be underestimated because of the simplifications of the calculation.
- In exceptional cases a residential building has no building rating point, when no façade points could be created because of its 3D geometry.
- Earlier FOEN publications on noise exposure are based on other input data and calculation methods and cannot be compared directly with the 2021 edition; no trends over time can be derived from them.
Notes on retrieval
- The façade points comprise about 36 million rows and can only be retrieved filtered, for example by road limit value class or sensitivity level. There is no prepared file for this dataset.
- The column Absolute elevation of the façade point is empty from 1000 m a.s.l. upwards; the complete height is in the point's 3D geometry.
- Rating points and façade points are delivered as 3D points, buildings and dwellings as 2D footprints, road sections as 2D lines, all in the LV95 coordinate system (EPSG:2056).
Download data
All datasets except the façade points are available as prepared GeoPackage files. Targeted extracts as GeoPackage, CSV or Parquet are available through the generic download and the GraphQL API.
Dateien werden geladen…
Licence and citation
Opendata BY: «Open use. Must provide the source.» (see Licence & source and opendata.swiss – terms of use). The data may only be reproduced with the source stated:
BAFU 2025, sonBASE – Lärmdatenbank Schweiz 2021.
Version: sonBASE21, version 1.0, as of 31.12.2021.
Glossary
| Term | Meaning |
|---|---|
| NAO (LSV) | Noise Abatement Ordinance. Annexes 3, 4 and 5 are the legal basis for determining and assessing road, railway and aircraft noise. |
| Lr | Rating level under the NAO, for road and railway noise for the periods day (06-22) and night (22-06). |
| Leq | Equivalent continuous sound level for an averaging period: day 06-18, day 06-22, evening 18-22, night 22-06. |
| LeqDEN | Day-evening-night level: weighted energetic sum of LeqTag_06_18, LeqAbend_18_22 and LeqNacht_22_06, with a 5 dB penalty for the evening and 10 dB for the night. |
| LeqDN | Day-night level: weighted energetic sum of LeqTag_06_22 and LeqNacht_22_06, with a 10 dB penalty for the night. |
| PW, IGW, AW | Planning value, immission limit value and alarm value: limit value classification under the NAO depending on the rating level, the noise sensitivity level (ES) and the use. |
| Dominant point day/night | States which of the two assessment periods shows the greater exceedance of the limit value. For every assessed object either the day or the night is dominant. |
| Partial level | Share of municipal, cantonal and national roads in the rating level of a façade point, for day and night. |
| EGID, EWID | Federal building and dwelling identifiers from the Federal Register of Buildings and Dwellings (RBD). |
| Permanent resident population | Swiss nationals with their main residence in Switzerland and foreign nationals with a residence permit for at least 12 months or after a stay of 12 months. |
| Swiss10 | Uniform classification of road traffic into ten vehicle categories, input to the sonROAD18 emission model. |
| sonROAD18, sonRAIL | Swiss emission models for road and railway noise. |
| Semibel | Swiss railway noise model, used in sonBASE 2021 for the propagation calculation. |
| ISO 9613-2 | International standard for calculating outdoor sound propagation, applied for road noise. |
Contact
Federal Office for the Environment, Noise and NIR Division: noise@bafu.admin.ch, subject «Lärmdaten 2021». For general questions about the data platform see Contact.