Facts
The decision concerns the planning approval for renovation measures on National Road N1 in the section Zurich North to Brüttisellen (sections 42 and 46), one of the busiest sections of Switzerland with an average daily traffic (ADT) of around 150,000 motor vehicles and peaks of over 10,000 vehicles per hour. The current speed limit is 100 km/h. The project includes, among other things, the installation of a low-noise road surface, the installation of a speed harmonisation and hazard warning system (GH/GW system), the construction of two new road wastewater treatment plants (SABA), five new noise protection walls (LSW) as well as the replacement of an existing LSW. In addition, permanent hard shoulder utilisation (PUN) for traffic flow optimisation is planned.
Objections to the project were raised by the City of Zurich and the Swiss Transport Club (VCS). The City of Zurich requested a finding of a substantial change to the road facility and a reduction of the speed limit to 80 km/h during the day and at night. The VCS requested, in the alternative, the introduction of a permanent speed limit of 80 km/h between 22:00 and 07:00. The Federal Office for the Environment (FOEN) requested a night-time speed reduction to 80 km/h (22:00–06:00).
The FDEA approved the project with planning approval dated 15 September 2020 subject to conditions and dismissed the objections of the City of Zurich and the VCS. Both parties appealed this decision to the Federal Administrative Court. The Federal Administrative Court partially granted the appeal of the City of Zurich by ordering the installation of soundproof windows in properties where noise limit values are exceeded, and dismissed the appeal of the VCS. The VCS and the City of Zurich then filed an appeal against these judgments with the Federal Supreme Court in public law matters.
Considerations
Planning law admissibility of permanent hard shoulder utilisation (PUN): The VCS argued that the PUN unlawfully deviated from the General Project (GP) as it introduced additional lanes and led to a massive expansion of the national road network. However, the Federal Supreme Court upheld the view of the Federal Administrative Court that the PUN does not constitute a structural extension of the main axis but rather a localised optimisation of entry and exit areas. The PUN is permissible as a traffic engineering adjustment since it does not result in a continuous increase in the number of lanes or a structural extension. The planning law objections were therefore dismissed as unfounded.
Noise protection law qualification of the measures: The Federal Supreme Court confirmed that the planned measures (PUN, low-noise road surface) do not constitute an "overweighted" change equating to a new installation. Instead, they represent an immaterial change for which only the noise emissions of the new components need to be limited. However, the Federal Administrative Court – and the Federal Supreme Court confirmed this – conducted a comprehensive assessment and qualified the measures as a "substantial change" within the meaning of Art. 8 para. 2 NAO, as the cumulative effect of the measures leads to a perceptible increase in noise (up to 0.9 dB(A)) and a significant capacity increase. This has the consequence that noise limit values (NLVs) must be complied with or exemptions may only be granted under strict conditions.
Proportionality of the night-time speed limit of 80 km/h: The appellants requested a night-time speed limit of 80 km/h between 22:00 and 07:00 to reduce noise pollution. The Federal Supreme Court examined the proportionality of this measure in the strict sense and concluded that the speed reduction is suitable and necessary to protect over 400 people from excessive noise. Although the cost-benefit analysis (CBA) according to NISTRA resulted in an unfavourable benefit-cost ratio due to the disproportionate weighting of travel time…