TRAFFIC NOISE
3.1.2.5 Schall 03: Guideline for the Calculation of Sound Immissions from Railways

Schall 03, the Guideline for the Calculation of Sound Immissions from Railways, gives instructions on how to conduct acoustic railway studies and serves as a basis for the calculation of railway noise according to the Traffic Noise Ordinance (16th Federal Immission Control Ordinance). It was introduced by the German Federal Railways (Deutsche Bundesbahn) and shall be used for the calculation of sound emissions and immissions in the proximity of railway and tram installations.

Schall 03 contains no information on noise measurements as the rating level shall principally be calculated.

Similar to RLS-90, the rating levels apply to light wind blowing from the sound source to the place of immission and if necessary to existing temperature inversions.

The guideline indicates a calculation method for the average sound level, considering local conditions like type of train, average amount of trains per hour, travel speed, train length, type of track (type of track bed) as well as the distance to the railway line. The impact of bridges, railway crossings and track curves is equally taken into account. The squeaking noises occurring in tight curves can lead to sound level additions of up to 8 dB(A).

A place of immission 3.5 m above the ground is assumed for the calculation of the rating levels on undeveloped territory; 0.2 m above the upper edge of the windows of the considered floor for the rating levels of buildings.

As railway noise is supposedly perceived as less disturbing than road traffic, a value of 5 dB(A) has so far been deducted from the calculated rating level. This railway bonus accounts for the "characteristic features of rail-borne traffic" as mentioned in § 43 of the Federal Immission Control Act. This privileges the otherwise environmentally friendly rail traffic over road traffic. But the railway bonus has been disputed among scientists for quite a time. The revision of the Federal Immission Control Act (BImSchG) came into effect on 6 July 2013 and it is going to repeal the railway bonus for the construction or major alteration of railway tracks as of 1 January 2015 and for urban railways and trams as of 1 January 2019.

Just like in RLS-90, the rating levels are calculated separately for day and night. As immission limit values during the night as prescribed in the Traffic Noise Ordinance are lower than during the day (see section 3.1.2.2), but emissions of railway traffic are often nearly identical at day and night (especially along cargo train routes), it suffices in many cases to carry out calculations only for the nighttime.

Schall 03 also contains calculation examples. Similar to RLS-90, the determination of rating levels on the basis of diagrams constitutes an estimation procedure.

A revision of Schall 03 is scheduled. It shall especially take into account new technologies, like the latest rail vehicles and modified brakes, but also alternative noise abatement measures along the route. As for emissions, a distinction shall be made between rolling noises, driving noises, aggregation sounds as well as aerodynamic noises. An estimation procedure is no longer intended.